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Document and Entity Information - USD ($) $ in Millions	12 Months Ended
Document and Entity Information - USD ($) $ in Millions	Dec. 31, 2019	Mar. 01, 2020	Jun. 28, 2019
Cover [Abstract]
Document Type	10-K
Document Period End Date	Dec. 31, 2019
Entity Registrant Name	Quanterix Corp
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	true
Entity Ex Transition Period	false
Entity Shell Company	false
Entity Public Float			$ 547
Entity Common Stock, Shares Outstanding		28,225,653
Entity Central Index Key	0001503274
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	FY
Amendment Flag	false

Consolidated Balance Sheet - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Current assets:
Cash and cash equivalents	$ 109,155	$ 44,429
Accounts receivable (less reserve for doubtful accounts of $162 and $36 as of December 31, 2019 and December 31, 2018, respectively; including $186 and $48 from related parties as of December 31, 2019 and December 31, 2018, respectively)	10,906	6,792
Inventory	10,463	5,945
Prepaid expenses and other current assets	2,137	2,330
Total current assets	132,661	59,496
Restricted cash	1,026	1,000
Property and equipment, net	12,047	2,923
Intangible assets, net	14,307	2,348
Goodwill	9,353	1,308
Other non-current assets	557	536
Total assets	169,951	67,611
Current liabilities:
Accounts payable (including $36 to related parties as of December 31, 2019 and December 31, 2018)	5,777	5,110
Accrued compensation and benefits	6,570	4,449
Other accrued expenses (including $0 and $226 to related parties as of December 31, 2019 and December 31, 2018, respectively)	2,498	3,129
Deferred revenue (including $55 and $33 with related parties as of December 31, 2019 and December 31, 2018, respectively)	4,697	5,437
Current portion of long term debt	75
Other current liabilities	216
Total current liabilities	19,833	18,125
Deferred revenue, net of current portion	466	520
Long term debt, net of current portion	7,587	7,623
Other non-current liabilities	13,407	278
Total liabilities	41,293	26,546
Commitments and contingencies (Note 9)
Stockholders’ equity:
Common stock, $0.001 par value: Authorized - 120,000,000 shares as of December 31, 2019 and December 31, 2018; issued and outstanding - 28,112,201 and 22,369,036 shares as of December 31, 2019 and December 31, 2018, respectively	28	22
Additional paid-in capital	345,027	216,931
Accumulated other comprehensive loss	(153)
Accumulated deficit	(216,244)	(175,888)
Total stockholders’ equity	128,658	41,065
Total liabilities and stockholders’ equity	$ 169,951	$ 67,611

Consolidated Balance Sheet (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Consolidated Balance Sheet
Accounts receivable, reserve for doubtful accounts	$ 162	$ 36
Accounts receivable, related parties	186	48
Accounts payable, related parties	36	36
Other accrued expenses, related parties	0	226
Deferred revenue, current, related parties	$ 55	$ 33
Share value	$ 0.001	$ 0.001
Common stock, authorized shares	120,000,000	120,000,000
Common stock, shares issued	28,112,201	22,369,036
Common stock, shares outstanding	28,112,201	22,369,036

Consolidated Statements of Operations - USD ($)	12 Months Ended
Consolidated Statements of Operations - USD ($)	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Revenue	$ 56,734,000	$ 37,632,000	$ 22,874,000
Cost of goods sold:
Total costs of goods sold and services	29,898,000	19,684,000	12,887,000
Gross profit	26,836,000	17,948,000	9,987,000
Operating expense:
Research and development (including stock compensation of $718, $513, and $180 for the years ended December 31, 2019, 2018, and 2017, respectively)	16,190,000	15,805,000	16,304,000
Selling, general and administrative (including stock compensation of $5,346, $4,143, and $1,912 for the years ended December 31, 2019, 2018, and 2017, respectively)	52,246,000	33,693,000	19,688,000
Total operating expenses	68,436,000	49,498,000	35,992,000
Loss from operations	(41,600,000)	(31,550,000)	(26,005,000)
Interest income (expense), net	627,000	46,000	(951,000)
Other income (expense), net	(10,000)	(7,000)	(63,000)
Loss before income tax	(40,983,000)	(31,511,000)	(27,019,000)
Income tax provision	187,000	(25,000)	0
Net loss	(40,796,000)	(31,536,000)	(27,019,000)
Reconciliation of net loss to net loss attributable to common stockholders:
Net loss	(40,796,000)	(31,536,000)	(27,019,000)
Accretion of preferred stock to redemption value			(4,110,000)
Accrued dividends on preferred stock			(59,000)
Net loss attributable to common stockholders	$ (40,796,000)	$ (31,536,000)	$ (31,188,000)
Net loss per share, basic and diluted	$ (1.63)	$ (1.43)	$ (8.30)
Weighted-average common shares outstanding, basic and diluted	25,090,708	21,994,317	3,756,954
Product revenue
Revenue	$ 40,491,000	$ 23,365,000	$ 14,124,000
Cost of goods sold:
Total costs of goods sold and services	20,900,000	12,729,000	7,742,000
Service and other revenue
Revenue	16,059,000	12,117,000	7,676,000
Cost of goods sold:
Total costs of goods sold and services	8,998,000	6,955,000	5,145,000
Collaboration and license revenue
Revenue	$ 184,000	$ 2,150,000	$ 1,074,000

Consolidated Statements of Operations (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Cost of product revenue, related party activity	$ 234	$ 191	$ 235
Stock compensation expense in cost of goods sold	86	55	24
Stock compensation expense in research and development expenses	718	513	180
Stock compensation expense in selling, general and administrative expenses	5,346	4,143	1,912
Product revenue
Related party revenue	720	294	339
Service and other revenue
Related party revenue	118	149	165
Stock compensation expense in cost of goods sold	238	173	52
Collaboration and license revenue
Related party revenue	$ 0	$ 2,150	$ 1,074

Consolidated Statements of Comprehensive Loss - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Consolidated Statements of Comprehensive Loss
Net income	$ (40,796)	$ (31,536)	$ (27,019)
Other comprehensive loss:
Cumulative translation adjustment	(153)
Total other comprehensive loss	(153)
Comprehensive loss	$ (40,949)	$ (31,536)	$ (27,019)

- Definition

The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

+ References + Details

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Operating activities
Net loss	$ (40,796)	$ (31,536)	$ (27,019)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization expense	3,009	1,352	482
Inventory valuation adjustment amortization	611
Stock-based compensation expense	6,388	4,884	2,168
Non-cash interest expense	89	170	238
Loss (gain) on disposal of fixed assets	140	(14)
Change in fair value of preferred stock warrants			90
Changes in operating assets and liabilities:
Accounts receivable	(3,365)	(983)	(1,682)
Prepaid expenses and other assets	289	(1,828)	(273)
Inventory	(3,447)	(1,603)	(2,043)
Other non-current assets	(21)	267
Accounts payable	621	1,318	1,003
Accrued compensation and benefits, other accrued expenses and other current liabilities	822	1,101	2,035
Contract acquisition costs	336
Other non-current liabilities	9,845
Deferred revenue	(708)	(1,849)	2,895
Net cash used in operating activities	(26,187)	(28,721)	(22,106)
Investing activities
Purchases of property and equipment	(10,847)	(1,518)	(1,132)
Purchase of investments		(150)
Acquisition of UmanDiagnostics AB, net of cash acquired	(14,529)	(3,801)
Proceeds from sale of assets		15
Net cash used in investing activities	(25,376)	(5,454)	(1,132)
Financing activities
Proceeds from sale of preferred stock, net of issuance costs			65,575
Proceeds from sale of common stock, net of issuance costs		(20)	8,423
Proceeds from exercise of stock warrants			29
Proceeds from stock options exercised	2,820	1,871	202
Proceeds from ESPP purchase	879
Proceeds from the issuance of notes payable and warrants, net of issuance costs			(59)
Payments on notes payable	(50)	(1,929)	(921)
Net cash provided by (used in) financing activities	116,197	(78)	73,249
Net increase (decrease) in cash and cash equivalents	64,634	(34,253)	50,011
Effect of foreign currency exchange rate on cash	118
Cash, restricted cash, and cash equivalents at beginning of period	45,429	79,682	29,671
Cash, restricted cash, and cash equivalents at end of period	110,181	45,429	79,682
Supplemental cash flow information
Accretion of preferred stock to redemption value			4,110
Cash paid for interest	656	606	743
Warrants issued to lenders			119
Purchases of property and equipment included in accounts payable	164	78
191,152 shares of common stock issued in connection with the acquisition of UmanDiagnostics AB	5,468
Purchases of property and equipment included in other non-current liabilities	7,572		74
Fair value of common stock warrants exercised and reclassified as shares of common stock		196	2,187
Reconciliation of cash, cash equivalents, and restricted cash:
Total cash, cash equivalents, and restricted cash	45,429	$ 79,682	$ 29,671
At-the-market offering
Financing activities
Proceeds from sale of common stock, net of issuance costs	48,019
Underwritten public offering
Financing activities
Proceeds from sale of common stock, net of issuance costs	$ 64,529

Consolidated Statements of Cash Flows (Parenthetical)	Aug. 01, 2019 shares
UmanDiagnostics AB Acquisition
Common stock shares consideration	191,152

Consolidated Statements of Redeemable Convertible Preferred Stock and Stockholders’ (Deficit) Equity - USD ($) $ in Thousands	Common stock Initial Public Offering	Common stock Underwritten public offering	Common stock At-the-market offering	Common stock	Additional paid-in capital Initial Public Offering	Additional paid-in capital Underwritten public offering	Additional paid-in capital At-the-market offering	Additional paid-in capital	Accumulated other comprehensive loss [Member]	Accumulated deficit	Series A Preferred Stock	Series B Preferred Stock	Series C Preferred Stock	Series D Preferred Stock	Initial Public Offering	Underwritten public offering	At-the-market offering	Total
Beginning Balance at Dec. 31, 2016				$ 2						$ (115,111)	$ 28,979	$ 17,459	$ 36,678	$ 45,469				$ (115,109)
Beginning balance (in shares) at Dec. 31, 2016				2,315,496							15,700,001	6,021,363	8,605,944	12,420,262
Increase (Decrease) in Stockholders' Equity
Exercise of preferred stock warrants											$ 2,078		$ 138
Exercise of preferred stock warrants (in shares)											700,000		31,283
Exercise of common stock options and vesting restricted stock								$ 204										204
Exercise of common stock options and vesting restricted stock (in shares)				289,321
Issue of common stock, net	$ 5				$ 65,570									$ 8,423	$ 65,575
Issue of common stock, net (in shares)	4,916,480													2,113,902
Accretion of preferred stock to redemption value								(2,029)		(2,081)	$ 1,080	$ 840	$ 2,140	$ 50				(4,110)
Conversion of preferred stock to common stock				$ 15				143,319			$ (32,137)	$ (18,299)	$ (38,956)	$ (53,942)				143,334
Conversion of preferred stock to common stock (in shares)				14,185,744							(16,400,001)	(6,021,363)	(8,637,227)	(14,534,164)
Warrant Liability reclassified to equity upon IPO								823										823
Stock-based compensation expense								2,168										2,168
Net loss										(27,019)								(27,019)
Ending Balance at Dec. 31, 2017				$ 22				210,196		(144,352)								65,866
Ending Balance (in shares) at Dec. 31, 2017				21,707,041
Increase (Decrease) in Stockholders' Equity
Cumulative-effect adjustment for the adoption of ASC 606								141		(141)
Exercise of preferred stock warrants (in shares)				16,718
Exercise of common stock options and vesting restricted stock								1,871										1,871
Exercise of common stock options and vesting restricted stock (in shares)				645,277
Common stock issuance offering costs								(20)										(20)
Stock-based compensation expense								4,884										4,884
Net loss										(31,536)								(31,536)
Ending Balance at Dec. 31, 2018				$ 22				216,931		(175,888)								41,065
Ending Balance (in shares) at Dec. 31, 2018				22,369,036
Increase (Decrease) in Stockholders' Equity
Exercise of preferred stock warrants (in shares)				45,690
Exercise of common stock options and vesting restricted stock								2,820										2,820
Exercise of common stock options and vesting restricted stock (in shares)				550,734
Issue of common stock, net		$ 3	$ 2			$ 64,526	$ 48,017									$ 64,529	$ 48,019
Issue of common stock, net (in shares)		2,732,673	2,186,163
Issuance of shares for acquisition of Uman				$ 1				5,467										5,468
Issuance of shares for acquisition of Uman (in shares)				191,152
ESPP stock purchase								878										878
ESPP stock purchase (in shares)				36,753
Stock-based compensation expense								6,388										6,388
Cumulative translation adjustment																		(153)
Net loss										(40,796)								(40,796)
Ending Balance at Dec. 31, 2019				$ 28				$ 345,027	$ (153)	(216,244)								128,658
Ending Balance (in shares) at Dec. 31, 2019				28,112,201
Increase (Decrease) in Stockholders' Equity
Cumulative-effect adjustment for the adoption of ASC 606										$ 440								440
Accumulated other comprehensive income									$ (153)									$ (153)

Consolidated Statements of Redeemable Convertible Preferred Stock and Stockholders' (Deficit) Equity (Parenthetical) $ in Thousands	12 Months Ended
	Dec. 31, 2017 USD ($)
Consolidated Statements of Redeemable Convertible Preferred Stock and Stockholders’ (Deficit) Equity
stock issuance cost	$ 8,173

Organization and operations	12 Months Ended
Organization and operations	Dec. 31, 2019
Organization and operations
Organization and operations	1. Organization and operations Quanterix Corporation (NASDAQ: QTRX) (the Company) is a life sciences company that has developed next generation, ultra-sensitive digital immunoassay platforms that advance precision health for life sciences research and diagnostics. The Company’s platforms are based on its proprietary digital “Simoa” detection technology. The Company’s Simoa bead-based and planar array platforms enable customers to reliably detect protein biomarkers in extremely low concentrations in blood, serum and other fluids that, in many cases, are undetectable using conventional, analog immunoassay technologies, and also allow researchers to define and validate the function of novel protein biomarkers that are only present in very low concentrations and have been discovered using technologies such as mass spectrometry. These capabilities provide the Company’s customers with insight into the role of protein biomarkers in human health that has not been possible with other existing technologies and enable researchers to unlock unique insights into the continuum between health and disease. The Company is currently focusing on protein detection, but is also developing its bead-based technology to detect nucleic acids in biological samples. The Company launched its first immunoassay platform, the Simoa HD-1, in 2014. The HD-1 is a fully automated immunoassay bead-based platform with multiplexing and custom assay capability, and related assay test kits and consumable materials. The Company launched a second bead-based immunoassay platform (SR-X) in the fourth quarter of 2017 with a more compact footprint than the Simoa HD-1 and less automation designed for lower volume requirements while still allowing multiplexing and custom assay capability. The Company initiated an early-access program for its third instrument (SP-X) on the new Simoa planar array platform in January 2019, with the full commercial launch commencing in April 2019. In July 2019, the Company launched the Simoa HD-X, an upgraded version of the Simoa HD-1 which replaces the HD-1. The HD-X has been designed to deliver significant productivity and operational efficiency improvements, as well as greater user flexibility. The Company began shipping and installing HD-X instruments at customer locations in the third quarter of 2019, ahead of its original fourth quarter expectation. The Company also performs research services on behalf of customers to apply the Simoa technology to specific customer needs. The Company's customers are primarily in the research use only market, which includes academic and governmental research institutions, the research and development laboratories of pharmaceutical manufacturers, contract research organizations, and specialty research laboratories. The Company acquired Aushon Biosystems, Inc. (Aushon) in January 2018. With the acquisition of Aushon, the Company acquired a CLIA certified laboratory, as well as Aushon’s proprietary sensitive planar array detection technology. Leveraging its proprietary sophisticated Simoa image analysis and data analysis algorithms, the Company further refined this planar array technology to develop the SP-X instrument to provide the same Simoa sensitivity found in its bead-based platform. The Company acquired UmanDiagnostics AB (Uman), a Swedish company located in Umeå, Sweden, in August 2019. The acquisition closed with respect to 95% of the outstanding shares of capital stock of Uman on July 1, 2019 and with respect to the remaining 5% of the outstanding shares of capital stock of Uman on August 1, 2019. Uman supplies neurofilament light (Nf-L) antibodies and ELISA kits, which are widely recognized by researchers and biopharmaceutical and diagnostics companies world-wide as the premier solution for the detection of Nf-L to advance the development of therapeutics and diagnostics for neurodegenerative conditions. With the acquisition of Uman, the Company has secured a long-term source of supply for a critical technology. Initial Public Offering In December 2017, the Company completed its initial public offering (IPO) in which the Company sold 4,916,480 shares of its common stock at the initial public offering price of $15.00 per share The Company’s common stock began trading on The Nasdaq Global Market on December 7, 2017. The aggregate net proceeds received from the IPO, net of underwriting discounts and commissions and offering expenses, was $65.6 million. Immediately prior to the completion of the IPO, all then outstanding shares of convertible preferred stock were converted into 14,185,744 shares of common stock. The related carrying value of shares of preferred stock and warrants in the aggregate amount of $143.3 million was reclassified as common stock and additional paid-in capital. Additionally, the Company filed an amended and restated certificate of incorporation with the Secretary of State of the State of Delaware, effective December 11, 2017 to, among other things, change the authorized number of shares of common stock to 120,000,000 and the authorized number of shares of preferred stock to 5,000,000. Reverse Stock Split On December 4, 2017, the Company effected a reverse stock split of its common stock at a ratio of 1‑for‑3.214. The shares of common stock subject to then outstanding stock options were adjusted accordingly to reflect the reverse stock split. All common stock and related per share amounts presented in these financial statements and related notes have been retroactively adjusted to reflect the 1‑for‑3.214 reverse stock split “At-the-market offering” On March 19, 2019, the Company entered into a Sales Agreement (the Sales Agreement) with Cowen and Company, LLC (Cowen) with respect to an “at-the-market” offering program under which the Company may offer and sell, from time to time at its sole discretion, shares of its common stock, par value $0.001 per share, having an aggregate offering price of up to $50.0 million through Cowen as its sales agent. On June 5, 2019, the Company issued approximately 2.2 million shares of common stock at an average stock price of $22.73 per share pursuant to the terms of the Sales Agreement. The “at-the-market” offering resulted in gross proceeds of $49.7 million. The Company incurred $1.7 million in issuance costs associated with the “at-the-market” offering, resulting in net proceeds to the Company of $48.0 million. Underwritten public offering On August 8, 2019, the Company entered into an underwriting agreement with J.P. Morgan Securities LLC and SVB Leerink LLC, as representatives of the several underwriters, relating to an underwritten public offering of approximately 2.7 million shares of the Company’s common stock, par value $0.001 per share. The underwritten public offering resulted in gross proceeds of $69.0 million. The Company incurred $4.5 million in issuance costs associated with the underwritten public offering, resulting in net proceeds to the Company of $64.5 million. Liquidity The Company has had recurring losses from operations since inception and has an accumulated deficit of $216.2 million at December 31, 2019 and the Company incurred a net loss of $40.8 million, $31.5 million, and $27.0 million for the years ended December 31, 2019, 2018, and 2017, respectively. Prior to the IPO the Company had funded its operations principally from issuances of preferred stock, debt financings, grants, product and service sales and development and license agreements. At December 31, 2019, the Company had $109.2 million of unrestricted cash and cash equivalents. The Company expects the current cash balance will be sufficient to fund operations for a period of at least one year from the date the consolidated financial statements are issued. There can be no assurances, however, that no additional funding will be required or that additional funding will be available on terms acceptable to the Company, or at all.

Significant accounting policies

12 Months Ended

Dec. 31, 2019

Significant accounting policies

Significant accounting policies

2. Significant accounting policies

Principles of consolidation

The consolidated financial statements have been prepared in accordance with U.S. GAAP and include the accounts of Quanterix Corporation, and its wholly-owned subsidiaries. All material intercompany transactions and balances have been eliminated in consolidation.

Use of estimates

The preparation of consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the amounts reported in the consolidated financial statements and accompanying notes. In making those estimates and assumptions, the Company bases its estimates on historical experience and on various other assumptions believed to be reasonable. The Company’s significant estimates included in the preparation of the consolidated financial statements are related to revenue recognition, fair value of equity instruments and notes receivable, fair value of assets acquired and liabilities assumed in acquisitions, valuation allowances recorded against deferred tax assets, and stock-based compensation. Actual results could differ from those estimates.

Revenue recognition

The Company recognizes revenue when a customer obtains control of a promised good or service. The amount of revenue recognized reflects consideration that the Company expects to be entitled to receive in exchange for these goods and services, incentives and taxes collected from customers, that are subsequently remitted to governmental authorities.

The Company adopted Accounting Standards Codification (ASC) Topic 606 Revenue from Contracts with Customers (ASC 606), on January 1, 2019, using the modified retrospective method for all contracts not completed as of the date of adoption. The reported results for 2019 reflect the application of ASC 606 guidance, while the reported results for 2018 were prepared under ASC 605, Revenue Recognition.

Customers

The Company’s customers primarily consist of entities engaged in the life sciences research market that pursue the discovery and development of new drugs for a variety of neurologic, cardiovascular, oncologic and other protein biomarkers associated with diseases. The Company’s customer base exceeds 730 customers and includes several of the largest biopharmaceutical companies, academic research organizations and distributors who serve certain geographic markets.

Product revenue

The Company’s products are composed of analyzer instruments, assay kits and other consumables such as reagents. Products are sold directly to biopharmaceutical and academic research organizations or are sold through distributors in EMEA and Asia Pacific regions. The sales of instruments are generally accompanied by an initial year of implied service-type warranties and may be bundled with assays and other consumables and may also include other items such as training and installation of the instrument and/or an extended service warranty. Revenues from the sale of products are recognized at a point in time when the Company transfers control of the product to the customer, which is upon installation for instruments sold to direct customers, and based upon shipping terms for assay kits and other consumables. Revenue for instruments sold to distributors is generally recognized based upon shipping terms (either upon shipment or delivery).

Service and other revenue

Service revenues are composed of contract research services, initial implied one-year service-type warranties, extended services contracts and other services such as training. Contract research services are provided through the Company’s Accelerator Laboratory and generally consist of fixed fee contracts. Revenues from contract research services are recognized at a point in time when the Company completes and delivers its research report on each individually completed study, or over time if the contractual provisions allow for the collection of transaction consideration for costs incurred plus a reasonable margin through the period of performance of the services. Revenues from service-type warranties are recognized ratably over the contract service period. Revenues from other services are immaterial.

Collaboration and license revenue

The Company may enter into agreements to license the intellectual property and know-how associated with its instruments in exchange for license fees and future royalties (as described below). The license agreements provide the licensee with a right to use the intellectual property with the license fee revenues recognized at a point in time as the underlying license is considered functional intellectual property. The Company has recognized revenues from a sales- or usage based royalties related to the Company’s licensing technology and intellectual property.

Payment terms

The Company’s payment terms vary by the type and location of customer and the products or services offered. Payment from customers is generally required in a term ranging from 30 to 45 days from date of shipment or satisfaction of the performance obligation with no discounts for early payment. Occasionally the Company provides extended payment terms or financing arrangements to customers.

Disaggregated Revenue

When disaggregating revenue, the Company considered all of the economic factors that may affect its revenues. The following tables disaggregate the Company's revenue from contracts with customers by revenue type:


	Year Ended
	December 31, 2019
(in thousands)	NA		EMEA		Asia Pacific		Total
Product revenues
Instruments	$	6,250	$	5,243	$	3,393	$	14,886
Consumable and other products		14,148		9,674		1,783		25,605
Totals	$	20,398	$	14,917	$	5,176	$	40,491

Service and other revenues
Service-type warranties	$	3,139	$	1,323	$	171	$	4,633
Research services		8,845		704		456		10,005
Other services		825		565		31		1,421
Totals	$	12,809	$	2,592	$	658	$	16,059

Collaboration and license revenue
Collaboration and license revenue	$	167	$	17	$	—	$	184
Totals	$	167	$	17	$	—	$	184

The Company’s contracts with customers may include promises to transfer multiple products and services to a customer. The Company combines any performance obligations that are immaterial with one or more other performance obligations that are material to the contract. For arrangements with multiple performance obligations, the Company allocates the contract transaction price, including discounts, to each performance obligation based on its relative standalone selling price. Judgment is required to determine the standalone selling price for each distinct performance obligation. The Company determines standalone selling prices based on prices charged to customers in observable transactions, and uses a range of amounts to estimate standalone selling prices for each performance obligation. The Company may have more than one range of standalone selling price for certain products and services based on the pricing for different customer classes.

Variable consideration in the Company’s contracts primarily relates to (i) sales- and usage-based royalties related to the license of intellectual property in collaboration and license contracts and (ii) certain non-fixed fee research services contracts. ASC 606 provides for an exception to estimating the variable consideration for sales- and usage-based royalties related to the license of intellectual property, such that the sales- or usage-based royalty will be recognized in the period the underlying transaction occurs. The Company has recorded sales- or usage-based royalty revenue for the year ended December 31, 2019 related to the intellectual property licensed by Uman. The Company recognizes revenues from sales- or usage based royalty revenue at the later of when the sales or usage occurs; and the satisfaction or partial satisfaction of the performance obligation to which the royalty has been allocated.

The aggregate amount of transaction price that is allocated to performance obligations that have not yet been satisfied or are partially satisfied as of December 31, 2019 is $5.2 million. Of the performance obligations not yet satisfied or are partially satisfied, $4.7 million is expected to be recognized as revenue in the next 12 months, with the remainder to be recognized within the 24 months thereafter. The $5.2 million principally consists of $3.0 million billed for undelivered services related to initial and extended service-type warranties and research services, as well as $1.7 million related to undelivered licenses of intellectual property for a diagnostics company.

Changes in deferred revenue from contracts with customers were as follows (in thousands):


	Year Ended December 31, 2019
Balance at December 31, 2018	$	5,957
606 adoption adjustment		(86)
Deferral of revenue		3,925
Recognition of deferred revenue		(4,633)
Balance at December 31, 2019	$	5,163

Costs to obtain a contract

The Company’s sales commissions are generally based on revenues of the Company. The Company has determined that certain commissions paid under its sales incentive programs meet the requirements to be capitalized as they are incremental and would not have occurred absent a customer contract. The change in the balance of costs to obtain a contract are as follows (in thousands):


	Year Ended December 31, 2019
Balance at December 31, 2018	$	—
606 adoption adjustment		307
Deferral of costs to obtain a contract		848
Recognition of costs to obtain a contract		(820)
Balance at December 31, 2019	$	335

The Company has classified the balance of capitalized costs to obtain a contract as a component of prepaid expenses and other current assets as of December 31, 2019 and classifies the expense as a component of cost of goods sold and selling, general and administrative expense over the estimated life of the contract. The Company considers potential impairment in these amounts each period.

ASC 606 provides entities with certain practical expedients and accounting policy elections to minimize the cost and burden of adoption.

The Company does not disclose the value of unsatisfied performance obligations for (i) contracts with original expected length of one year or less and (ii) contracts for which revenue is recognized at the amount to which the Company has the right to invoice for services performed.

The Company will exclude from its transaction price any amounts collected from customers related to sales and other similar taxes.

When determining the transaction price of a contract, an adjustment is made if payment from a customer occurs either significantly before or significantly after performance, resulting in a significant financing component. The Company does not assess whether a significant financing component exists if the period between when the Company performs its obligations under the contract and when the customer pays is one year or less. None of the Company’s contracts contained a significant financing component as of December 31, 2019.

The Company has elected to account for the shipping and handling as an activity to fulfill the promise to transfer the product, and therefore will not evaluate whether shipping and handling activities are promised services to its customers.

Business combinations

Under the acquisition method of accounting, the Company allocates the fair value of the total consideration transferred to the tangible and identifiable intangible assets acquired and liabilities assumed based on their estimated fair values on the date of acquisition. The fair values assigned, defined as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between willing market participants, are based on estimates and assumptions determined by management. The excess consideration over the aggregate fair value of tangible and intangible assets, net of liabilities assumed, is recorded as goodwill. These valuations require significant estimates and assumptions, especially with respect to intangible assets.

The Company typically uses the discounted cash flow method to value acquired intangible assets. This method requires significant management judgment to forecast future operating results and establish residual growth rates and discount factors. The estimates used to value and amortize intangible assets are consistent with the plans and estimates that are used to manage the business and are based on available historical information. If the subsequent actual results and updated projections of the underlying business activity change compared with the assumptions and projections used to develop these values, the Company could experience impairment charges. In addition, the Company has estimated the economic lives of certain acquired assets and these lives are used to calculate depreciation and amortization expense. If estimates of the economic lives change, depreciation or amortization expenses could be accelerated or slowed.

Cost of revenue

Cost of product revenue consists of raw materials, parts costs and associated freight, shipping and handling costs, contract manufacturer costs, personnel costs, yield loss, in-license payments and royalties, stock-based compensation, other direct costs and overhead.

Cost of service and other revenue consists of personnel, facility costs associated with operating the Accelerator Labs on behalf of the customers, costs related to instrument maintenance and servicing equipment at customer sites, other direct and overhead.

Cost of license revenue, related party consists of license fees that are the direct results of cash payments received related to license agreements.

Research and development expenses

Research and development expenses, including personnel costs, allocated facility costs, lab supplies, outside services, contract laboratory costs are charged to research and development expense as incurred. The Company accounts for nonrefundable advance payments for goods and services that will be used in future research and development activities as expense when the service has been performed or when the goods have been received.

Selling, general, and administrative expenses

Selling, general, and administrative expenses are primarily composed of compensation and benefits associated with sales and marketing, finance, human resources, and other administrative personnel, outside marketing, advertising, allocated facilities costs, legal expenses, and other general and administrative costs.

Net loss per share

Basic net loss per common share attributable to common stockholders is calculated by dividing the net loss attributable to common stockholders by the weighted-average number of common shares. For purposes of the diluted net loss per share calculations, preferred stock, unvested restricted common stock, and common stock options are considered to be potentially dilutive securities, but are excluded from the diluted net loss per share because their effect would be anti-dilutive and therefore basic and diluted net loss per share were the same for all periods presented.

The following table sets forth the outstanding potentially dilutive securities that have been excluded in the calculation of diluted net loss per share because to do so would be anti-dilutive (in common stock equivalent shares):


	Year Ended December 31,
	2019	2018	2017
Unvested restricted common stock and restricted stock units	409,929	361,468	177,192
Outstanding stock options	2,507,062	2,476,911	2,249,843
Outstanding common stock warrants	10,000	76,041	86,090
Total	2,926,991	2,914,420	2,513,125

As of December 31, 2019, 2018, and 2017 the Company had an obligation to issue warrants to purchase an additional 93,341 shares of common stock to a vendor if a contract is terminated prior to a minimum purchase commitment being met. No amounts are presented in the table above for this obligation to issue a warrant as the issuance of the warrant is not considered probable.

Cash and cash equivalents

Cash and cash equivalents consist of cash deposits and short-term, highly liquid investments that are readily convertible into cash, with original maturities of three months or less. Cash equivalents are carried at fair value based on quoted prices for identical assets. Cash and cash equivalents consist of the following (in thousands):


	As of
	December 31,
	2019		2018
Cash	$	6,406	$	1,821
Money market funds invested in U.S. Treasury obligations		102,749		42,608
Total cash and cash equivalents	$	109,155	$	44,429

Restricted cash and deposits

Restricted cash represents collateral for a letter of credit issued as security for the lease for the Company’s new headquarters. The restricted cash is long term in nature as the Company will not have access to the funds until more than one year from December 31, 2019.

As of December 31, 2019 and 2018, the Company had $1.1 million and $1.4 million, respectively, in restricted cash and deposits related to amounts held for a line of credit, amounts held as a security deposit for the Company’s facility lease obligation, and a business registration application. As of December 31, 2019, $1.0 million of the $1.1 million was recorded on a separate line item as restricted cash. The remaining $0.1 million was included in noncurrent assets. As of December 31, 2018, $1.0 million of the $1.4 million was recorded on a separate line item as restricted cash. The remaining $0.4 million was included in current and noncurrent assets.

Accounts receivable and allowance for doubtful accounts

The Company provides credit, in the normal course of business, to customers and does not require collateral. Accounts receivable consist of amounts due to the Company for sales to customers and are recorded net of an allowance for doubtful accounts. The Company reviews accounts receivable on a regular basis to determine if any receivable will potentially be uncollectable and to estimate the amount of allowance for doubtful accounts necessary. Once a receivable is deemed uncollectible, such balance is written off and charged against the allowance for doubtful accounts. The Company has not incurred material write offs in any of the periods presented.

Inventory

Inventory is stated at the lower of cost or market on a first-in, first-out (FIFO) basis. The Company analyzes its inventory levels on each reporting date and writes down inventory that is expected to expire prior to being sold and inventory in excess of expected sales requirements. In the event that the Company identifies these conditions exist in its inventory, the carrying value is reduced to its estimated net realizable value.

Property and equipment

Property and equipment, including leasehold improvements, are stated at cost and are depreciated, or amortized in the case of leasehold improvements, over their estimated useful lives using the straight-line method. Expenditures for maintenance and repairs are charged to expense as incurred, whereas major betterments are capitalized as additions to property and equipment. The Company reviews its property and equipment whenever events or changes in circumstances indicate that the carrying value of certain assets might not be recoverable and recognizes an impairment loss when it is probable that an asset’s realizable value is less than the carrying value. To date, no such impairment losses have been recorded. Depreciation is calculated based upon the following estimated useful lives of the assets:


Laboratory and manufacturing equipment		Five years
Computers and software		Three years
Office furniture and equipment		Seven years
Leasehold improvements		Shorter of the useful life of the asset or the remaining term of the lease

Software development costs

The Company develops and modifies software related to the operation of the instrument. Software development costs are expensed as incurred until the point the Company establishes technological feasibility. Based on the Company’s product development process, technological feasibility is established upon the completion of a working model. The Company does not incur material costs between the completion of the working model and the point at which the product is ready for release. Therefore, software development costs are charged to the statement of operations as incurred as research and development expense.

Investments

During 2016, the Company purchased a minority interest in preferred stock in a privately held company for $0.3 million. During 2018, the Company was issued a convertible note by a privately held company having a principal amount of $0.2 million.

The preferred stock investment is recorded on a cost basis in other non-current assets on the accompanying balance sheets as the Company does not have a controlling interest, does not have the ability to exercise significant influence over the privately held company, and the fair value of the equity investment is not readily determinable. The Company performs an impairment analysis at each reporting period to determine if there is any readily available fair value information that would indicate an impairment. The Company has determined there was no impairment during the year ended December 31, 2019 or in any prior period.

The convertible note is held as an available-for-sale investment, which is carried at fair market value, with the unrealized gains and losses included in the determination of comprehensive loss. When determining the estimated fair value of the convertible notes, the Company used a commonly accepted valuation methodology.

Equity investments that do not result in consolidation and are not accounted for under the equity method are measured at fair value, with any changes in fair value recognized in net income. For any such investments that do not have readily determinable fair values, the Company elects the measurement alternative to measure the investments at cost minus impairment, if any, plus or minus changes resulting from observable price changes in orderly transactions for the identical or a similar investment of the same issuer.

Fair value of financial instruments

ASC Topic 820, Fair Value Measurement (ASC 820), establishes a fair value hierarchy for instruments measured at fair value that distinguishes between assumptions based on market data (observable inputs) and the Company’s own assumptions (unobservable inputs). Observable inputs are inputs that market participants would use in pricing the asset or liability based on market data obtained from sources independent of the Company. Unobservable inputs are inputs that reflect the Company’s assumptions about the inputs that market participants would use in pricing the asset or liability, and are developed based on the best information available in the circumstances.

ASC 820 identifies fair value as the exchange price, or exit price, representing the amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants. As a basis for considering market participant assumptions in fair value measurements, ASC 820 establishes a three-tier fair value hierarchy that distinguishes between the following:

Level 1 inputs are quoted prices (unadjusted) in active markets for identical assets or liabilities.

Level 2 inputs are inputs other than quoted prices that are observable for the asset or liability, either directly or indirectly; and

Level 3 inputs are unobservable inputs that reflect the Company’s own assumptions about the assumptions market participants would use in pricing the asset or liability.

To the extent that the valuation is based on models or inputs that are less observable or unobservable in the market, the determination of fair value requires more judgment. Accordingly, the degree of judgment exercised by the Company in determining fair value is greatest for instruments categorized in Level 3. A financial instrument’s level within the fair value hierarchy is based on the lowest level of any input that is significant to the fair value measurement.

The carrying amount reflected on the balance sheets for cash and cash equivalents, accounts receivable, prepaid expenses and other current assets, accounts payable and accrued liabilities approximated their fair values, due to the short-term nature of these instruments. The carrying value of the long-term debt approximates its fair value as the debt arrangement is based on interest rates the Company believes it could obtain for borrowings with similar terms. The Company has an investment in the preferred stock of a privately held company which is recorded within other non-current assets on a cost basis. This cost method investment’s fair value has not been estimated as there are no identified events or changes in circumstances that would indicate a significant adverse effect on the fair value of the investment and to do so would be impractical.

Fair value measurements as of December 31, 2019 are as follows (in thousands):


			Quoted prices				Significant
			in active		Significant other		unobservable
			markets		observable		inputs
Description	Total		(Level 1)		inputs (Level 2)		(Level 3)
Financial assets
Cash equivalents	$	109,155	$	109,155	$	—	$	—
Note receivable		150		—		—		150
	$	109,305	$	109,155	$	—	$	150

Fair value measurements as of December 31, 2018 are as follows (in thousands):


			Quoted prices				Significant
			in active		Significant other		unobservable
			markets		observable		inputs
Description	Total		(Level 1)		inputs (Level 2)		(Level 3)
Financial assets
Cash equivalents	$	42,608	$	42,608	$	—	$	—
Note receivable		150		—		—		150
	$	42,758	$	42,608		—	$	150

Warranties

The Company provides a one-year warranty and maintenance service related to its instruments and sells extended warranty contracts for additional periods. The Company defers revenue associated with these services and recognizes them on a pro-rata basis over the period of service.

Income taxes

The Company recognizes deferred tax assets and liabilities for the expected future tax consequences of events that have been recognized in the Company’s consolidated financial statements or tax returns. Under this method, deferred tax assets and liabilities are determined based on differences between the consolidated financial statement carrying amounts and the tax bases of the assets and liabilities using the enacted tax rates in effect in the years in which the differences are expected to reverse. A valuation allowance against deferred tax assets is recorded if, based on the weight of the available evidence, it is more likely than not that some or all of the deferred tax assets will not be realized.

The Company accounts for uncertain tax positions in accordance with the provisions of ASC 740 Income Taxes (ASC 740). When uncertain tax positions exist, the Company recognizes the tax benefit of tax positions to the extent that the benefit will more likely than not be realized. The determination as to whether the tax benefit will more likely than not be realized is based upon the technical merits of the tax position as well as consideration of the available facts and circumstances. As of December 31, 2019 and 2018, the Company did not have any significant uncertain tax positions.

Credit, product and supplier concentrations and off-balance-sheet risk

The Company has no significant off-balance-sheet risk, such as foreign exchange contracts, option contracts, or other hedging arrangements. Financial instruments that potentially expose the Company to concentrations of credit risk primarily consist of cash and cash equivalents and a cost method investment. The Company places its cash and cash equivalents principally in depository accounts with a bank.

The Company is also subject to supply chain risks related to the outsourcing of the manufacturing of its instruments. Although there are a limited number of manufacturers for instruments of this type, the Company believes that other suppliers could provide similar products on comparable terms. A change in suppliers, however, could cause a delay in manufacturing and a possible loss of sales, which would adversely affect operating results. In addition to outsourcing the manufacturing of its instruments, the Company also purchases antibodies through a number of different suppliers. Although a disruption in service from any one of its antibody suppliers is possible, the Company believes that it would be able to find an adequate supply from alternative suppliers.

Customers outside the United States represented 50% and 40% of the Company’s gross trade accounts receivable balance as of December 31, 2019 and 2018, respectively.

At December 31, 2019 and 2018, no single customer represented 10% of the Company’s aggregate accounts receivable, and no single customer represented 10% of the Company’s revenue for the year ended December 31, 2019 and 2018. At December 31, 2017, one customer represented 10% of the Company’s revenue for the year ended December 31, 2017.

Stock-based compensation

The Company accounts for stock-based compensation awards in accordance with ASC 718, Compensation—Stock Compensation. ASC 718 requires all stock-based payments to employees, including grants of employee stock options, to be recognized in the statement of operations based on their fair values. Stock-based compensation awards have historically consisted of stock options and restricted stock.

Effective January 1, 2017, the Company ceased utilizing an estimated forfeiture rate and began recognizing forfeitures as they occur. The Company estimates the grant date fair value, and the resulting stock-based compensation expense, using the Black-Scholes option-pricing model. The grant date fair value of the stock-based awards is generally recognized on a straight-line basis over the requisite service period, which is generally the vesting period of the respective awards.

The Company recognizes compensation costs related to share-based payments granted to non-employees, which consists of directors for their services on the board of directors, based on the estimated fair value of the awards on the date of grant in the same manner as options for employees. There were no material non-employee awards outstanding during the years ended December 31, 2019, 2018, and 2017.

The fair value of stock options granted to employees and non-employees is estimated on the grant date using the Black-Scholes option-pricing model, based on the assumptions noted in the following table:


	Year Ended December 31,
	2019	2018	2017
Risk-free interest rate	1.4% - 2.6%	2.6% - 3.0%	1.8% - 2.1%
Expected dividend yield	None	None	None
Expected term (in years)	6.0	5.9	6.0
Expected volatility	33.5% - 39.7%	32.4% - 36.8%	46.0% - 52.0%

Using the Black-Scholes option-pricing model, the weighted-average grant date fair value of options granted for the years ended December 31, 2019, 2018, and 2017 was $9.09, $7.19, and $4.52 per share, respectively. Expected volatility was calculated based a propotional weighting of reported volatility data for a representative group of guideline publicly traded companies for which historical information was available and the Company’s stock. The risk-free interest rate is based on the U.S. Treasury yield curve in effect at the time of grant, commensurate with the expected life assumption. The Company estimates the expected life of options granted to employees utilizing the simplified method which calculates the expected life of an option as the average of the time to vesting and contractual life of the options. The expected life is applied to the stock option grant group as a whole, as the Company does not expect substantially different exercise or post-vesting termination behavior among its employee population. The Company uses the simplified method due to the lack of historical exercise data and the plain nature of the stock options. The Company uses the remaining contractual term for the expected life of non-employee awards. The expected dividend yield is assumed to be zero as the Company has never paid dividends and has no current plans to pay any dividends on common stock.

Recent accounting pronouncements

The Company is considered to be an “emerging growth company” as defined in the Jumpstart Our Business Startups Act of 2012, as amended (JOBS Act). The JOBS Act provides that an emerging growth company can take advantage of an extended transition period for complying with new or revised accounting standards. Thus, an emerging growth company can delay the adoption of certain accounting standards until those standards would otherwise apply to private companies. The Company has elected to avail itself of this extended transition period and, as a result, the Company will not be required to adopt new or revised accounting standards on the relevant dates on which adoption of such standards is required for other public companies so long as the Company remains an emerging growth company.

On January 1, 2019, the Company adopted ASC 606 using the modified retrospective method. Under ASC 606, revenue is recognized upon the transfer of control of goods or services to customers and reflects the amount of consideration to which an entity expects to be entitled in exchange for those goods or services. The adoption of ASC 606 has been applied to customer contracts that were not completed as of January 1, 2019, and did not materially change the pattern of revenue recognition for its current customer contracts.

The Company's consolidated financial statements for the prior-year period have not been revised and are reflective of the revenue recognition requirements which were in effect for that period.

The Company recorded an adjustment to the accumulated deficit of $0.4 million as of January 1, 2019 for the cumulative effect primarily related to the deferral of sales commissions.

In accordance with the reporting requirements of ASC 606, the disclosure of the impact on the Company's consolidated balance sheet and statement of operations, as a result of adopting the provisions of ASC 606, was as follows (in thousands):


											Prior to
											adoption of
	As				Adjusted under		As reported				ASC 606
	reported				ASC 606		December 31,				December 31,
	December 31, 2018		Adjustments		January 1, 2019		2019		Adjustments		2019
Assets:
Accounts receivable	$	6,792	$	47	$	6,839	$	10,906	$	—	$	10,906
Prepaid expenses and other current assets		2,330		288		2,618		2,137		335		1,802
Other non-current assets		536		19		555		557		—		557

Liabilities:
Deferred revenue		5,437		43		5,394		4,697		(209)		4,488
Deferred revenue, net of current portion		520		43		477		466		14		480

Stockholders’ equity:
Accumulated deficit	$	(175,888)	$	(440)	$	(175,448)	$	(216,244)	$	(140)	$	(216,104)


	For the Year Ended December 31, 2019
					Under ASC
	Under ASC 606		Adjustment		605
Product revenue	$	40,491	$	55	$	40,546
Service revenue		16,059		273		16,332
Costs of goods sold and services		29,898		1		29,899
Gross profit		26,836		327		27,163
Selling general and administrative expenses		52,246		27		52,273
Net loss	$	(40,796)	$	300	$	(40,496)

In January of 2019, the Company adopted accounting standards update (ASU) 2016-01, which requires equity investments (except those accounted for under the equity method of accounting or those that result in consolidation of the investee) to be measured at fair value with changes in fair value recognized in net income. For equity investments without readily determinable fair values that do not qualify for the practical expedient to estimate fair value using the net asset value per share or its equivalent, the Company has elected to measure these investments at cost minus impairment, if any, plus or minus changes resulting from observable price changes in orderly transactions for the identical or similar investment of the same issuer. This election is made for each investment separately and is reassessed at each reporting period as to whether the investment continues to qualify for this election. Additionally, at each reporting period, the Company makes a qualitative assessment considering impairment indicators to evaluate whether the investment is impaired. The adoption of this standard did not have a material effect on the Company’s consolidated financial statements.

In February 2016, the FASB established Topic 842, Leases, by issuing ASU No. 2016-02, which requires lessees to recognize leases on-balance sheet and disclose key information about leasing arrangements. Topic 842 was subsequently amended by ASU No. 2018-01, Land Easement Practical Expedient for Transition to Topic 842; ASU No. 2018-10, Codification Improvements to Topic 842, Leases; and ASU No. 2018-11, Targeted Improvements. The new standard establishes a right-of-use model (ROU) that requires a lessee to recognize a ROU asset and lease liability on the balance sheet for all leases with a term longer than 12 months. Leases will be classified as finance or operating, with classification affecting the pattern and classification of expense recognition in the income statement. A modified retrospective transition approach is required, applying the new standard to all leases existing at the date of initial application. The new standard is effective for the Company on January 1, 2020, with early adoption permitted. The Company expects to adopt the new standard on January 1, 2020 and use the effective date as the date of initial application.

In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments — Credit Losses: Measurement of Credit Losses on Financial Instruments (ASU 2016-13), which amends the impairment model by requiring entities to use a forward-looking approach based on expected losses to estimate credit losses on certain types of financial instruments, including trade receivables and available-for-sale debt securities. In April 2019 the FASB issued ASU 2019-04, Codification Improvements to Topic 326, Financial Instruments - Credit Losses, in May 2019, the FASB issued ASU 2019-05, Financial Instruments - Credit Losses (ASC 326) Targeted Relief, and in November 2019, the FASB issued ASU 2019-11, Codification Improvements to Topic 326, Financial Instruments - Credit Losses. These recently issued ASUs do not change the core principle of the guidance in ASU 2016-13 but rather are intended to clarify and improve operability of certain topics included within ASU 2016-13. ASU 2018-19, ASU 2019-04, ASU 2019-05 and ASU 2019-11 have the same effective date and transition requirements as ASU 2016-13. The new guidance will become effective for the Company beginning in fiscal year 2021, with early adoption permitted. The new guidance is required to be applied on a modified-retrospective basis. The Company is currently evaluating the impact of this standard on its consolidated financial statements and disclosures.

In January 2017, the FASB issued ASU No. 2017‑04 Intangibles—Goodwill and Other (Topic 350)—Simplifying the Test for Goodwill Impairment. This ASU eliminates Step 2 from the goodwill impairment test. In addition, income tax effects from any tax deductible goodwill on the carrying amount of the reporting unit should be considered when measuring the goodwill impairment loss, if applicable. The amendments also eliminate the requirements for any reporting unit with a zero or negative carrying amount to perform a qualitative assessment and, if it fails that qualitative test, to perform Step 2 of the goodwill impairment test. An entity still has the option to perform the qualitative assessment for a reporting unit to determine if the quantitative impairment test is necessary. This ASU is effective for annual periods beginning after December 15, 2019 and interim periods within those annual periods. Early adoption is permitted, for interim or annual goodwill impairment tests performed on testing dates after January 1, 2017. The Company does not expect adoption of this ASU to be material to its financial statements on known trends, demands, uncertainties and events in its business. The Company plans to adopt ASU 2017-04 as of January 1, 2020 and does not expect that the adoption of this guidance will have a material effect on its consolidated financial statements.

In August 2018, the FASB issued ASU No. 2018‑13, “Fair Value Measurement (Topic 820), Disclosure Framework—Changes to the Disclosure Requirements for Fair Value Measurement”. This ASU removed the following disclosure requirements: (1) the amount of and reasons for transfers between Level 1 and Level 2 of the fair value hierarchy; (2) the policy for timing of transfers between levels; and (3) the valuation processes for Level 3 fair value measurements. Additionally, this update added the following disclosure requirements: (1) the changes in unrealized gains and losses for the period included in other comprehensive income for recurring Level 3 fair value measurements held at the end of the reporting period; (2) the range and weighted average of significant unobservable inputs used to develop Level 3 fair value measurements. For certain unobservable inputs, an entity may disclose other quantitative information (such as the median or arithmetic average) in lieu of the weighted average if the entity determines that other quantitative information would be a more reasonable and rational method to reflect the distribution of unobservable inputs used to develop Level 3 fair value measurements. ASU 2018‑13 will be effective for fiscal years beginning after December 15, 2019 with early adoption permitted. As of December 31, 2019, the Company has not elected to early adopt this guidance but does not expect that the adoption of this guidance will have a material effect on its consolidated financial statements.

In November 2019, the FASB issued ASU 2019-08, Compensation ‒ Stock Compensation (Topic 718) and Revenue from Contracts with Customers (Topic 606), which requires entities to measure and classify share based payments to a customer, in accordance with the guidance in ASC 718, Compensation ‒ Stock Compensation. The amendments in that ASU expanded the scope of Topic 718 to include share-based payment transactions for acquiring goods and services from nonemployees and, in doing so, superseded guidance in Subtopic 505-50, Equity ‒ Equity-Based Payments to Non-Employees. The amount that would be recorded as a reduction in revenue would be measured based on the grant date fair value of the share based payment, in accordance with Topic 718. The grant date is the date at which a supplier and customer reach a mutual understanding of the award’s key terms and conditions. The award’s classification and subsequent measurement would be subject to ASC 718 unless the award is modified or the grantee is no longer a customer. For entities that have not yet adopted the amendments in ASU 2018-07, the amendments in this ASU are effective for (1) public business entities in fiscal years beginning after December 15, 2019, and interim periods within those fiscal years, and (2) other than public business entities in fiscal years beginning after December 15, 2019, and interim periods within fiscal years beginning after December 15, 2020. For entities that have adopted the amendments in ASU 2018-07, the amendments in this ASU are effective in fiscal years beginning after December 15, 2019, and interim periods within those fiscal years. An entity may early adopt the amendments in this ASU, but not before it adopts the amendments in ASU 2018-07. The Company is currently evaluating the impact the adoption of the standard will have on the Company’s financial position or results of operations.

In December 2019, the FASB issued ASU 2019-12, Income Taxes (ASC 740): Simplifying the Accounting for Income Taxes, which is intended to simplify various areas related to accounting for income taxes. ASU 2019-12 removes certain exceptions to the general principles in ASC 740 and also clarifies and amends existing guidance to improve consistent application. ASU 2019-12 is effective for the Company beginning in fiscal year 2022, with early adoption permitted. The Company is currently evaluating the impact of this standard on its consolidated financial statements and disclosures.

Inventory

12 Months Ended

Dec. 31, 2019

Inventory

Inventory

3. Inventory

Inventory consists of the following (in thousands):


	As of
	December 31,
	2019		2018
Raw materials	$	4,717	$	1,546
Work in process		2,573		2,331
Finished goods		3,173		2,068
Total	$	10,463	$	5,945

Inventory comprises commercial instruments, assays, and the materials required to manufacture assays.

Property and equipment

12 Months Ended

Dec. 31, 2019

Property and equipment

Property and equipment

4. Property and equipment

Property and equipment consists of the following (in thousands):


	As of
	December 31,
	2019		2018
Laboratory and manufacturing equipment	$	5,391	$	4,127
Office furniture and equipment		1,403		789
Computers and software		1,103		786
Leasehold improvements		8,489		244
		16,386		5,946
Less: accumulated depreciation		(4,339)		(3,023)
Total	$	12,047	$	2,923

The Company incurred depreciation expense of $1.6 million and $0.7 million for the years ended December 31, 2019 and 2018, respectively. The Company has instruments included in laboratory and manufacturing equipment, which are used internally by the Company. The laboratory and manufacturing equipment balance includes $2.8 million of cost and $1.2 million of accumulated depreciation related to these instruments.

Other accrued expenses

12 Months Ended

Dec. 31, 2019

Other accrued expenses

Other accrued expenses

5. Other accrued expenses

Other accrued expenses consist of the following (in thousands):


	As of December 31,
	2019		2018
Accrued inventory	$	459	$	599
Accrued royalties		476		323
Accrued professional services		655		723
Accrued development costs		151		795
Accrued other		757		689
Total accrued expenses	$	2,498	$	3,129

Other non-current liabilities consist of the following (in thousands):


	As of December 31,
	2019		2018
Leasehold obligation incentive	$	7,572	$	—
Deferred rent		3,009		265
Deferred tax liabilities		2,825		7
Other		1		6
Total non-current liabilities	$	13,407	$	278

Income taxes

12 Months Ended

Dec. 31, 2019

Income taxes

Income taxes

6. Income taxes

The following table presents the components of loss before income taxes (in thousands):


	Year Ended December 31,
	2019		2018		2017
United States	$	(40,010)	$	(31,436)	$	(27,019)
Foreign		(973)		(75)		—
	$	(40,983)	$	(31,511)	$	(27,019)

The following table summarizes income tax benefit (provision) (in thousands):


	Year Ended
	December 31,
	2019		2018		2017
Current:
United States
Federal	$	—	$	—	$	—
State		(20)		(18)		—
Foreign		(93)		—		—
Total current income tax provision		(113)		(18)		—
Deferred
United States
Federal		(3)		(2)		—
State		(1)		(5)		—
Foreign		304		—		—
Total deferred income tax benefit (provision)		300		(7)		—
Total income tax benefit (provision)	$	187	$	(25)	$	—

During the years ended December 31, 2019, 2018, and 2017, the Company recorded an income tax benefit (provision) of $0.2 million, less than $(0.1) million, and $0, respectively.

A reconciliation of the federal statutory income tax rate to the effective tax rate is as follows:


	Year Ended December 31,
	2019		2018
Federal statutory income tax rate	21.0	%	21.0	%
Foreign tax rate differential	—	%	—	%
State taxes, net of federal benefit	3.2	%	6.0	%
Tax credits	2.3	%	2.7	%
Share-based compensation	2.3	%	1.1	%
Permanent items	(0.9)	%	(1.2)	%
Defereed tax rate changes	(1.4)	%	—	%
Change in valuation allowance	(24.6)	%	(29.9)	%
Other	(1.4)	%	0.2	%
Effective income tax rate	0.5	%	(0.1)	%

The effective tax rate of 1% differs from the U.S. Federal statutory rate of 21% primarily as a result of the valuation allowance maintained against our worldwide net deferred tax assets.

During 2018, the Company acquired Aushon. The Company analyzed the transaction from an income tax perspective and adjusted the deferred tax assets and liabilities related to the Aushon acquisition. Of the total goodwill recorded, approximately $0.4 million is amortizable related to historical tax basis that Aushon had related to a prior acquisition.

During 2019, the Company acquired Uman, a Swedish entity. The Company analyzed the transaction from an income tax perspective and found that there was no tax deductible goodwill or other identifiable intangible assets related to the transaction.

Deferred tax assets and liabilities reflect the net tax effects of net operating loss carryovers and temporary differences between the carrying amount of assets and liabilities for financial reporting and the amounts used for income tax purposes. Significant components of the Company’s deferred tax assets and liabilities were as follows (in thousands):


	December 31,
	2019		2018
Deferred tax assets:
Net operating loss carryforwards	$	43,814	$	35,623
Tax credits		5,518		4,678
Deferred revenue		1,247		1,614
Depreciation		—		86
Amortization		928		792
Stock-based compensation		973		541
Deferred Rent		727		—
Lease incentive obligation		1,828		—
Other deferred tax assets		1,325		1,378
Total deferred tax assets		56,360		44,712
Less: Valuation allowances		(54,137)		(44,033)
Net deferred tax assets		2,223		679
Deferred tax liabilities:
Section 481(a) adjustment - accrued bonus		—		(59)
Depreciation		(1,769)		—
Amortization of acquired intangibles		(3,031)		(610)
Inventory		(212)		—
Goodwill		(31)		(17)
Other deferred tax liabitlies		(5)		—
Net deferred tax assets (liabilities)	$	(2,825)	$	(7)

The valuation allowance increased by $10.1 million during the year ended December 31, 2019, primarily as a result of the U.S. operating losses incurred, the research and development tax credit carryforwards generated during the year.

In determining the need for a valuation allowance, the Company has given consideration to the cumulative book income and loss positions of each of its entities as well as its worldwide cumulative book loss position. The Company has assessed, on a jurisdictional basis, the available means of recovering deferred tax assets, including the ability to carryback net operating losses, the existence of reversing taxable temporary differences, the availability of tax planning strategies and forecasted future taxable income. At December 31, 2019, the Company maintains a full valuation allowance against its worldwide net deferred tax assets.

As of December 31, 2019, the Company had U.S. federal net operating loss carryforwards of approximately $174.8 million. U.S. federal net operating loss carryforwards generated through December 31, 2017 of approximately $108.5 million expire at various dates through 2037, and U.S. federal net operating loss carryforwards generated in the tax years beginning after December 31, 2017 of approximately $66.3 million do not expire. As of December 31, 2019 the Company had $111.9 million of state net operating loss carryforwards that expire at various dates through 2039. As of December 2019, the Company had U.S. federal tax carryforwards of approximately $4.3 million that expire at various dates through 2039. As of December 31, 2019, the Company had U.S. state tax credit carryforwards of approximately $1.6 million that expire at various dates through 2034.

Under Sections 382 and 383 of the U.S. Internal Revenue Code, if a corporation undergoes an ownership change, the corporation’s ability to use its pre-change net operating loss carryforwards and other pre-change tax attributes, such as research tax credits, to offset its post-change income and taxes may be limited. In general, an ownership change generally occurs if there is a cumulative change in its ownership by 5% stockholders that exceeds 50 percentage points over a rolling three-year period. Similar rules may apply under U.S. state tax laws. The Company may have experienced an ownership change in the past and may experience ownership changes in the future as a result of future transactions in its share capital, some of which may be outside of the control of the Company. As a result, if the Company earns net taxable income, its ability to use its pre-change net operating loss carryforwards, or other pre-change tax attributes, to offset U.S. federal and state taxable income and taxes may be subject to significant limitations.

The Company accounts for uncertain tax positions using a more likely than not threshold for recognizing uncertain tax positions. The evaluation of uncertain tax positions is based on factors that include, but are not limited to, changes in tax law, the measurement of tax positions taken or expected to be taken in tax returns, the effective settlement of matters subject to audit, new audit activity and changes in facts or circumstances related to a tax position. The Company evaluates uncertain tax positions on an ongoing basis and adjusts the level of the liability to reflect any subsequent changes in the relevant facts surrounding the uncertain positions. The Company accounts for interest and penalties related to uncertain tax positions as a component of its provision for income taxes. For the years ended December 31, 2019, 2018, and 2017, the Company had no tax reserves accrued for uncertain tax positions and there are no accrued interest or penalties in the consolidated statements of operations.

The Company is subject to taxation in the United States as well as the Netherlands, Sweden, and China. At December 31, 2019, the Company is generally no longer subject to examination by taxing authorities in the United States for years prior to 2016. However, net operating loss carryforwards and credits in the United States may be subject to adjustments by taxing authorities in future years in which they are utilized. The Company’s foreign subsidiaries remain open to examination by taxing authorities from 2014 onward.

As of December 31, 2019, the Company’s foreign subsidiaries had immaterial undistributed earnings and the tax payable on the earnings that are indefinitely reinvested would be immaterial.

Redeemable convertible preferred stock	12 Months Ended
Redeemable convertible preferred stock	Dec. 31, 2019
Redeemable convertible preferred stock
Redeemable convertible preferred stock	7. Redeemable convertible preferred stock The Company had authorized 47,015,449 shares of preferred stock, $0.001 par value per share, of which 3,972,415 shares were designated Series A‑1 redeemable convertible preferred stock (Series A‑1 Preferred Stock), 10,492,027 shares were designated Series A‑2 Preferred Stock, 2,000,000 shares were designated Series A‑3 Preferred Stock, 6,186,594 shares were designated Series B Preferred Stock, 9,247,089 shares were designated as Series C Preferred Stock, 544,332 shares were designated Series C‑1 redeemable convertible preferred stock (Series C‑1 Preferred Stock), 12,459,090 shares were designated Series D Preferred Stock and 2,113,902 were designated Series D‑1 redeemable convertible preferred stock (Series D‑1 Preferred Stock) as of immediately prior to the completion of the IPO. In January 2017, the Company issued 700,000 shares of Series A‑3 Preferred Stock to a vendor (Note 8) upon the exercise of Series A‑3 Preferred Stock warrants at a purchase price of $0.001 per share. The fair value of the settled warrant was $2.1 million at the time of exercise which was reclassified from Preferred Stock Warrant Liability to Series A Preferred Stock. In June 2017, the Company issued 2,113,902 shares of Series D‑1 Preferred Stock at a purchase price of $4.021 per share. The issuance resulted in cash proceeds of $8.4 million, net of issuance costs. In November 2017, the Company issued 31,283 shares of Series C Preferred Stock upon exercise of Series C Preferred Stock warrants, which included 8,474 shares of Series C Preferred Stock at a purchase price of $3.3299 per share, and 22,809 shares of Series C Preferred Stock upon a cashless exercise of a warrant. The fair value of the settled warrants was $0.1 million at the time of exercise which was reclassified from Preferred Stock Warrant Liability to Series C Preferred Stock. The Company had a Stock Purchase Agreement (SPA) with bioMérieux, a related party, which required the Company to issue additional shares of Series C Preferred Stock if certain milestones were met in exchange for $10.0 million in gross proceeds. The milestones were related to activities under a Joint Development and License Agreement (JDLA) (Note 13). bioMérieux also purchased Series C Preferred Stock when the JDLA was entered into in 2012. When the SPA was entered into, the Company evaluated whether the requirement to issue additional shares (‘Tranche Feature") required separate accounting. The Company determined that the Tranche Feature was not legally detachable and therefore was an embedded feature in the Series C Preferred Stock that bioMérieux purchased. All preferred stock automatically converted to common stock at the time of the Company’s IPO.

Common Stock, warrants, stock-based compensation, stock options, restricted stock and restricted stock units

12 Months Ended

Dec. 31, 2019

Common Stock, warrants, stock-based compensation, stock options, restricted stock and restricted stock units

Common Stock, warrants, stock-based compensation, stock options, restricted stock and restricted stock units

8. Common Stock, warrants, stock-based compensation, stock options, restricted stock and restricted stock units

Common stock reserved

The Company reserved the following shares of common stock, on a common stock equivalent basis, for the conversion of shares of preferred stock, the exercise of warrants, the exercise of common stock options, and the vesting of restricted common stock.


	As of December 31,
	2019	2018
Common stock warrants	10,000	76,041
Common stock options and unvested restricted common stock	2,916,991	2,838,402
Shares reserved for future awards under compensation plan	882,715	2,433,999
	3,809,706	5,348,442

Warrants

The following table summarizes the Company’s outstanding warrants as of December 31, 2019, and 2018:


		Weighted
	Issued and	Average
	exercisable	Exercise Price
As of December 31, 2018	76,041	$	10.10
Issued	—
Exercised	(66,041)		10.90
Cancelled	—
As of December 31, 2019	10,000	$	4.83

The Company has an agreement with a vendor (Note 9) where the Company could be obligated to issue warrants to purchase an additional 93,341 shares of common stock to the vendor if the contract is terminated prior to a minimum purchase commitment being met. No shares have been reserved related to these potential obligations to issue warrants in the future. On January 30, 2018, the Company issued a warrant to purchase 10,000 of common stock to a consultation company for services rendered.

On July 2, 2019, 66,041 warrants were exercised by a holder on a net, non-cash, basis. Per terms of the warrant agreement, the Company issued 45,690 shares of common stock after giving effect to the holder’s net excercise.

Stock-based compensation

Share-based compensation expense for all stock awards consists of the following (in thousands):


	December 31,
	2019		2018		2017
Cost of product revenue	$	86	$	55	$	24
Cost of service and other revenue		238		173		52
Research and development		718		513		180
Selling, general, and administrative		5,346		4,143		1,912
Total	$	6,388	$	4,884	$	2,168

In June 2007, the Company adopted the 2007 Stock Option and Grant Plan (the 2007 Plan), under which it could grant incentive stock options, non-qualified options, restricted stock, and stock grants. At December 31, 2016, the 2007 Plan allowed for the issuance of up to 3,229,935 shares of common stock. During the three months ended March 31, 2017, the 2007 Plan was amended to allow for the issuance of an additional 622,227 shares of common stock for a total issuance of up to 3,852,213 shares of common stock at June 30, 2017. During the three months ended September 30, 2017 the 2007 Plan was further amended to allow for the issuance of an additional 497,822 shares of common stock for total issuance of up to 4,350,035 shares of common stock at September 30, 2017. As of December 31, 2017, under the 2007 Plan, options to purchase 2,249,843 shares of the Company’s common stock were outstanding, 571,838 shares of common stock had been issued and were outstanding pursuant to the exercise of options, 1,128,975 shares of common stock had been issued and were outstanding pursuant to restricted or unrestricted stock awards, and 399,379 shares of common stock were available for future awards. In connection with the completion of the IPO, the Company terminated the 2007 Plan. As of December 31, 2019, 1,221,746 shares were outstanding and no shares were available for future grant under the 2007 Plan.

In December 2017, the Company adopted the 2017 Employee, Director and Consultant Equity Incentive Plan (the 2017 Plan), under which it may grant incentive stock options, non-qualified stock options, restricted stock, and other stock-based awards. As of December 31, 2017, the 2017 Plan allowed for the issuance of up to 1,042,314 shares of common stock plus up to 2,490,290 shares of common stock represented by awards granted under the 2007 Plan that are forfeited, expire or are cancelled without delivery of shares or which result in the forfeiture of shares of common stock back to the Company on or after the date the 2017 Plan becomes effective. As of December 31, 2019 and 2018, there were shares available for grant under the 2017 Plan of 270,143 and 4,393, respectively.

In addition, the 2017 Plan contains an "evergreen" provision, which allows for an annual increase in the number of shares of common stock available for issuance under the 2017 Plan on the first day of each fiscal year during the period beginning in fiscal year 2019 and ending in fiscal year 2027. The annual increase in the number of shares shall be equal to the lowest of: 4% of the number of shares of common stock outstanding as of such date; and an amount determined by the Company’s Board of Directors or Compensation Committee. On January 1, 2020, the number of shares of common stock available for issuance under the 2017 plan was automatically increased by 894,761 shares.

In December 2017, the Company adopted the 2017 Employee Stock Purchase Plan (the 2017 ESPP). As December 31, 2018, the 2017 ESPP allowed for the issuance of up to 425,533 shares of common stock. As of December 31, 2019, 612,572 shares were available for grant under the 2017 ESPP.

In addition, the 2017 ESPP contains an "evergreen" provision, which allows for an increase on the first day of each fiscal year beginning with fiscal year 2018. The increase in the number of shares shall be equal to the lowest of: 1% of the number of shares of common stock outstanding on the last day of the immediately preceding fiscal year or an amount determined by the Company’s Board of Directors or Compensation Committee.

The 2017 ESPP provides for six-month option periods commencing on March 1 and ending August 31 and commencing September 1 and ending February 28 of each calendar year. The first offering under the 2017 ESPP began on September 1, 2018.

Stock options

Under the 2007 and 2017 Plans, stock options may not be granted with exercise prices of less than fair market value on the date of the grant. Options generally vest ratably over a four-year period with 25% vesting on the first anniversary and the remaining 75% vesting ratably on a monthly basis over the remaining three years. These options expire ten years after the grant date. Activity under the 2007 Plan and the 2017 Plan were as follows:


		Weighted-average		Remaining contractual	Aggregate intrinsic value
	Options	exercise price		life (in years)	(in thousands)
Outstanding at December 31, 2018	2,476,911	$	9.65	7.73	$	22,108
Granted	882,959	$	24.20
Exercised	(414,672)	$	6.80
Cancelled	(438,136)	$	14.37
Outstanding at December 31, 2019	2,507,062	$	14.41	7.58	$	24,870
Vested and expected to vest at December 31, 2019	2,507,062	$	14.41	7.58	$	24,870
Exercisable at December 31, 2019	1,284,900	$	8.70	6.46	$	19,239

Using the Black-Scholes option pricing model, the weighted-average fair value of options granted to employees and directors during the years ended December 31, 2019, 2018, and 2017 was $9.09, $7.19, and $4.52 per share, respectively. The expense related to stock options granted to employees was $3.7 million, $2.7 million, and $1.5 million for the years ended December 31, 2019, 2018, and 2017, respectively. The intrinsic value of stock options exercised was $6.9 million, $5.3 million, and $1.1 million, for the years ended December 31, 2019, 2018, and 2017, respectively. Activity related to non-employee awards was not material to the years ended December 31, 2019, 2018, and 2017.

At December 31, 2019, there was $8.7 million of total unrecognized compensation cost related to unvested stock options, which is expected to be recognized over the remaining weighted-average vesting period of 2.77 years.

Restricted stock awards

In December 2014, the Company issued 78,912 shares of restricted common stock to a director of the Company under the 2007 Plan. Under the terms of the agreement, shares of common stock issued are subject to a four year vesting schedule. Vesting occurs periodically at specified time intervals and specified percentages. In January 2015, the Company issued 781,060 shares of restricted common stock to an executive of the Company under the 2007 Plan. The majority of these shares were issued subject to a four year vesting schedule with 25% vesting on the first anniversary and the remaining vesting 75% ratably on a monthly basis over the remaining three years, while another portion was issued subject to performance based vesting. The vesting of performance based awards is dependent upon achievement of specified financial targets of the Company. The majority of the performance criteria were achieved during the years ended December 31, 2016 and 2015 and the remaining unvested awards with performance conditions are not material. No restricted stock awards were granted during the years ended December 31, 2019, 2018, or 2017. As of December 31, 2019, the Company had 39,806 shares of unvested restricted common stock with a weighted average grant date fair value of $3.12 per share.

The expense related to restricted stock awards granted to employees and non-employees was $0.0 million, $0.4 million, and $0.6 million for the years ended December 31, 2019, 2018, and 2017, respectively.

At December 31, 2019, there was no unrecognized compensation cost related to unvested restricted stock.

The aggregate fair value of restricted stock awards that vested during the years ended December 31, 2019, 2018, and 2017, based on estimated fair values of the stock underlying the restricted stock awards on the day of vesting, was $0.0 million, $2.4 million and $1.9 million, respectively.

Restricted stock units

Restricted stock units (RSUs) represent the right to receive shares of common stock upon meeting specified vesting requirements. In the fiscal year ended December 31, 2019, the Company issued 246,588 RSUs to employees of the Company under the 2017 Plan. Under the terms of the agreements, 135,058 of the RSUs issued are subject to a four year vesting schedule with 25% vesting on the first anniversary and the remaining vesting 75% ratably on a monthly basis over the remaining three years, 40,846 of the RSUs are subject to a four year vesting schedule with 25% vesting on each anniversary, 15,890 of the RSUs vested on December 31, 2019, 10,194 of the RSUs vested with respect to 5/48th of the shares on the date of grant with the rest vesting ratably over the remaining 43 months; 31,732 of the RSUs vested with respect to 1,983 shares vesting on the grant date with the rest vesting ratably over the remaining 45 months; 4,540 of the RSUs vest equally over three years on the anniversary of the vesting start date; 3,000 of the RSUs vest upon the one year anniversary of the grant date; and 5,328 vested immediately upon grant. A summary of RSU activity is as follows:


		Weighted-average
		grant date
		fair value
	Shares	per share
Unvested RSUs as of December 31, 2018	321,662	$	15.84
Granted	246,588	$	24.22
Vested	(136,062)	$	17.11
Cancelled	(62,065)	$	18.82
Unvested RSUs as of December 31, 2019	370,123	$	20.48

The expense related to RSU awards granted to employees and directors was $2.7 million for the fiscal year ended December 31, 2019.

At December 31, 2019, there was $6.9 million of total unrecognized compensation cost related to unvested restricted stock, which is expected to be recognized over the remaining weighted-average vesting period of 2.78 years.

Commitments and contingencies

12 Months Ended

Dec. 31, 2019

Commitments and contingencies

Commitments and contingencies

9. Commitments and contingencies

License agreements

Tufts University

In June 2007, the Company entered into a license agreement (the License Agreement) for certain intellectual property with Tufts University (Tufts). Tufts is a related party to the Company due to Tuft’s equity ownership in the Company and because a board member of the Company’s Board of Directors was affiliated with Tufts. The License Agreement, which was subsequently amended, is exclusive and sub licensable, and will continue in effect on a country by country basis as long as there is a valid claim of a licensed patent in a country. The Company is committed to pay license and maintenance fees, prior to commercialization, in addition to low single digit royalties on direct sales and services and a royalty on sublicense income. During the year ended December 31, 2016, the Company executed a license agreement with a diagnostic company and also amended the bioMérieux agreement (Note 13). During the years ended December 31, 2019, 2018 and 2017, the Company recorded royalty expense of $1.0 million, $0.7 million and $0.5 million, respectively, in cost of product revenue on the consolidated statements of operations.

Other licenses

During the year ended December 31, 2012, the Company entered into a license agreement for certain intellectual property with a third party. The non-exclusive, non-sublicenseable third party’s license provides the Company access to certain patents specifically for protein detection, and shall be in effect until the expiration of the last licensed patent. In consideration for these rights, the Company committed to certain license fees, milestone payments, minimum annual royalties and a mid-single digit royalty. The Company is required to make mid-single digit royalty payments on net sales of products and services which utilize the licensed technology. The Company must pay the greater of calculated royalties on net sales or an annual minimum royalty of $50 thousand. During the year ended December 31, 2019, 2018 and 2017, the Company recorded royalty expense of $0.8 million, $0.4 million, and $0.2 million, respectively, in cost of product revenue on the consolidated statements of operations.

Lease commitments

During the year ended December 31, 2014, the Company entered into a lease agreement for the Company’s former corporate headquarters with a lease term that expires in June 2020; however, in November 2018, the Company agreed to terminate the lease with the lessor effective May 2019. The termination of the lease was connected to the Company signing a new lease in Billerica, Massachusetts. On October 2, 2018, the Company entered into a 137-month operating lease for the Company’s new headquarters in Billerica, Massachusetts. The lease is for approximately 92,000 square feet of office and laboratory space, and commenced on or about April 1, 2019. The lease contains a period of free rent and escalating monthly rent payments. As part of the lease, the Company was required to enter into a $1.0 million Letter of Credit drawable by the lessor under specifically outlined conditions. The amount of the Letter of Credit will be reduced at 41 and 65 months after the commencement date of the lease to $750,000 and then $250,000, respectively. The $1.0 million Letter of Credit is recorded as restricted cash on the consolidated balance sheet.

In connection with the acquisition of Aushon in January 2018, the Company assumed the existing Aushon lease for facilities in Billerica, Massachusetts. In August 2018 the Company terminated the Aushon lease effective September 1, 2019. The Company paid a termination fee of $75,000 in February 2019 in consideration for the early termination.

In connection with the acquisition of Uman in August 2019, the Company assumed the existing Uman leases for the facilities in Umeå, Sweden.

Rent expense is recognized straight-line over the course of the lease term. As of December 31, 2019, $3.0 million of deferred rent expense was recorded in other non-current liabilities. The table below includes committed lease expenditures related to the new lease.

As of December 31, 2019, the minimum future rent payments under the lease agreements are as follows (in thousands):


2020	$	2,081
2021		3,322
2022		3,396
2023		3,480
2024 and Forward		25,760
	$	38,039

The Company recorded $3.3 million, $1.6 million and $1.1 million in rent expense for the years ended December 31, 2019, 2018, and 2017, respectively.

Development and supply agreement

Through the Company’s development agreement with STRATEC Biomedical, as amended in December 2016, the parties agreed on additional development services for an additional fee, which is payable when the additional development is completed. A total of $11.7 million is payable to STRATEC Biomedical upon completion of the development activities. This amount is being recorded to research and development expense and accrued expenses as the services are performed. The services were completed during the year ended December 31, 2018. Substantive efforts related to these additional development activities started in the first quarter of 2019 and were completed in the third quarter of 2019.

The Company’s supply agreement with STRATEC Biomedical requires the Company to purchase a minimum number of commercial units over a seven‑year period ending in May 2021. If the Company were to fail to purchase a required number of commercial units, the Company would be obligated to pay termination costs plus a fee based on the shortfall of commercial units purchased compared to the required minimum amount. Based on the number of commercial instruments purchased as of December 31, 2019, assuming no additional commercial units were purchased, this fee would equal $9.6 million. The amount the Company could be obligated to pay under the minimum purchase commitment is reduced as each commercial unit is purchased. Also, if the Company terminates the supply agreement under certain circumstances and has not purchased a required number of commercial units, it would be obligated to issue warrants to purchase 93,341 shares of common stock (the Supply Warrants) at $0.003214 per share. The Company believes that it will purchase sufficient units to meet the requirements of the minimum purchase commitment and, therefore, has not accrued for any of the potential cash consideration. The Supply Warrants are accounted for at fair value; however, the fair value of the Supply Warrants as of December 31, 2019 and December 31, 2018 was insignificant as there was a low probability of the warrants being issued.

Legal contingencies

The Company is subject to claims in the ordinary course of business; however, the Company is not currently a party to any pending or threatened litigation, the outcome of which would be expected to have a material adverse effect on its financial condition or the results of its operations. The Company accrues for contingent liabilities to the extent that the liability is probable and estimable.

Long term debt

12 Months Ended

Dec. 31, 2019

Long Term Debt

Long term debt

10. Long term debt

Loan agreement

On April 14, 2014, the Company executed a Loan Agreement with a lender, as subsequently amended, most recently in April 2019. As of December 31, 2019, there were no additional amounts available to borrow under the debt facility. The interest rate on this term loan is variable based on a calculation of the prime rate less 5.25% with a minimum interest rate of 8%. Interest is paid monthly beginning the month following the borrowing date. At loan inception and in connection with the amendments, the Company issued the lender warrants to purchase shares of stock. The Loan Agreement also contains prepayment penalties and an end of term charge. Fees incurred upon execution of the agreements, and the fair value of warrants on the date of grant were accounted for as a reduction in the book value of debt and accreted through interest expense, using the effective interest rate method, over the term of the debt.

Amendment 5 to loan agreement

In August 2018, the Company signed Amendment 5 to the Loan Agreement (Amendment 5). Amendment 5 instituted a 2018 End of Term Charge of $0.08 million. Additionally, the Term Loan Maturity Date extended until March 1, 2020. Amendment 5 additionally, changed the due date of the End of Term Charge to, the earlier of (i) the Term Loan Maturity Date, (ii) the date that Borrower prepays the outstanding Secured Obligations or (iii) the date that the Secured Obligations become due and payable. The Company incurred a cost of $0.05 million in relation to the execution of Amendment 5. In connection with the extension of the due date of the Loan, the deferral of principal payments (Amendment 3) was further deferred until the new Term Loan Maturity Date.

Amendment 6 to loan agreement

In October 2018, the Company signed Amendment 6 to the Loan agreement, which amended the Loan Agreement’s collateral clause to exclude the $1 million certificate of deposit associated with the lease on the Company’s new headquarters in Billerica, MA.

Amendment 7 to loan agreement

On April 15, 2019, the Company signed Amendment 7 to the Loan Agreement, which extended the interest only payment period through July 1, 2021 and also extended the maturity date until October 1, 2021. As part of this Amendment 7, a “2019 End of Term Fee” for $50,000 was added to the Loan Agreement due on the earliest to occur of (i) the Term Loan Maturity Date, (ii) the date that the Company prepays the outstanding Secured Obligations and (iii) the date that the Secured Obligations become due and payable. In addition, the Company is required to pay the loan principal in five equal installments starting July 1, 2021 with the final principal payment to be made on October 1, 2021. As of December 31, 2019, the remaining loan balance is classified as a long term liability since all principal payments are due greater than twelve months after the balance sheet date.

No end of term charges related to the facility or principal payments were paid during the fiscal year ended December 31, 2019. Under the terms of the April 2019 amended agreement, principal payments were delayed until July 2021. The Company accounted for the April 2019 amendment as a modification as it was determined that no material change occurred as a result of the amendment. Under the amended Loan Agreement, the remaining outstanding principal will be paid equally from July 2021 through October 2021. As of December 31, 2019, the remaining loan balance is classified as a long term liability since all principal payments are due greater than twelve months after the balance sheet date.

As of December 31, 2019, debt payment obligations due based on principal payments are as follows (in thousands):


2020	$	—
2021		7,688
	$	7,688

Non-cash interest expense related to debt discount amortization and accretion of end of term fees was $0.1 million, $0.2 million, and $0.2 million for the year ended December 31, 2019, 2018, and 2017, respectively.

The Company assessed all terms and features of the Loan Agreement and the subsequent amendments in order to identify any potential embedded features that would require bifurcation. As part of this analysis, the Company assessed the economic characteristics and risks of the debt. The Company determined that all features of the Loan Agreement and the subsequent amendments are either clearly and closely associated with a debt host or have a de minimis fair value and, as such, do not require separate accounting as a derivative liability. The Company assessed each amendment under ASC 470‑50 Debt – Modifications and Extinguishments and concluded that all of the amendments constituted modifications. The Company also assessed whether the amendments represented a troubled debt restructuring and concluded they did not. The Company accounted for each of the amendments to the Loan Agreement as a modification of its debt and the unamortized discount and issuance costs related to the prior debt are amortized over the modified term of the new debt.

The Loan Agreement and the subsequent amendments contain negative covenants restricting the Company’s activities, including limitations on dispositions, mergers or acquisitions, incurring indebtedness or liens, paying dividends or making investments and certain other business transactions. There are no financial covenants associated with the Loan Agreement and the subsequent amendments. The obligations under the Loan Agreement and subsequent amendments are subject to acceleration upon the occurrence of specified events of default, including a material adverse change in the Company’s business, operations or financial or other condition. The Company has determined that the risk of subjective acceleration under the material adverse events clause is not probable and therefore has classified the outstanding principal in current and long-term liabilities based on scheduled principal payments.

At-the-market offering	12 Months Ended
At-the-market offering	Dec. 31, 2019
At-the-market offering
At-the-market offering	11. “At-the-market offering” On March 19, 2019, the Company entered into the Sales Agreement with Cowen with respect to an “at-the-market” offering program under which the Company may offer and sell, from time to time at its sole discretion, shares of its common stock, having an aggregate offering price of up to $50.0 million through Cowen as its sales agent. On June 5, 2019, the Company issued approximately 2.2 million shares of common stock at an average stock price of $22.73 per share pursuant to the terms of the Sales Agreement. The “at-the-market” offering resulted in gross proceeds of $49.7 million. The Company incurred $1.7 million in issuance costs associated with the “at-the-market” offering, resulting in net proceeds to the Company of $48.0 million.

Underwritten public offering	12 Months Ended
Underwritten public offering	Dec. 31, 2019
Underwritten public offering
Underwritten public offering	12. Underwritten public Offering On August 8, 2019, the Company entered into an underwriting agreement with J.P. Morgan Securities LLC and SVB Leerink LLC, as representatives of the several underwriters, relating to an underwritten public offering of approximately 2.7 million shares of the Company’s common stock, par value $0.001 per share. The underwritten public offering resulted in gross proceeds of $69.0 million. The Company incurred $4.5 million in issuance costs associated with the underwritten public offering, resulting in net proceeds to the Company of $64.5 million.

Collaboration and license arrangements

12 Months Ended

Dec. 31, 2019

Collaboration and license arrangements

Collaboration and license arrangements

13. Collaboration and license arrangements

In November 2012, the Company entered into the JDLA with bioMérieux, a related party. As discussed below, the JDLA has been subsequently amended. Under the terms the JDLA, the Company granted bioMérieux an exclusive, royalty-bearing license, without right to sublicense, to manufacture and sell instruments and assays using the Company’s Simoa technology exclusively for in vitro diagnoses used in clinical lab applications, food quality control testing, and pharma quality control testing, and co-exclusively in certain related fields, as defined in the contract. As part of the JDLA, the Company was also to develop and manufacture instruments to bioMérieux’s specifications for bioMérieux’s use or for sale by bioMérieux. The Company retained rights to sell the instrument in the co-exclusive fields and any other fields not licensed exclusively to bioMérieux. bioMérieux was to develop and sell diagnostic assays to be used in conjunction with the Company’s instruments.

Upon execution of the JDLA, the Company received $10.0 million in consideration and was entitled to receive two additional payments of $5.0 million each upon the achievement of certain developmental criteria. Neither of these criteria have been achieved. The Company was also entitled to receive royalty payments on the sale of assays and payments for the manufacture and delivery of instruments based on a contractual rate subject to future adjustments.

At the inception of the JDLA, the Company determined that the deliverables were as follows: (1) licenses to the Company’s technology and trademarks, training, completion and delivery of a prototype instrument per contractual specifications (License and Prototype), (2) various activities to assist bioMérieux in the development of the initial assay and an instrument that is IVD compliant (Initial Assay Assistance), (3) various activities to assist bioMérieux in the development of a benchtop instrument (Benchtop Assistance), and (4) joint steering committee participation (JSC). Each of these deliverables were considered separate units of accounting, and the License and Prototype unit of accounting was determined to have standalone value as the License and Prototype unit of accounting could be utilized by bioMérieux without the related services included in the other units of accounting.

The Company allocated the allocable arrangement consideration based on the relative selling price of each unit of accounting. For all units of accounting, the Company determined the selling price using the standalone selling price (SSP). Management’s best estimate of the selling price of the License and Prototype unit of accounting was based on a discounted cash flow analysis to support the estimated selling price of the license. The Company determined the SSP of the other units of accounting based on internal estimates of the costs to perform the services, adjusted to reflect a reasonable profit margin as well as based on market prices for similar instruments and services.

Revenue related to the License and Prototype unit of accounting of $8.3 million was recognized in 2013 upon delivery of both the license which was delivered at inception, and the first prototype instrument, which was required for bioMérieux to make use of the license. Prior to the effect of the 2016 Amendment described below, revenue for the other units of accounting were recognized over an estimated period of performance.

Amendments to the JDLA

In May 2014 and January 2015, the parties executed a First and Second Amendment to the JLDA, respectively. These amendments addressed revised timelines related to completing the development activities under the JDLA and enacted additional governance protocols to monitor those activities.

These amendments did not change the deliverables under the JDLA or the total arrangement consideration. The Company revised its estimates of the remaining period of performance for the remaining undelivered units of accounting and these revisions did not have a material effect on revenue recognition.

On December 22, 2016, the Company entered into the 2016 Amendment which ended the ongoing joint development efforts between the parties, and modified the rights and obligations of both parties accordingly, as follows:

For a period of not more than three years from the date of the 2016 Amendment bioMérieux had the ability to evaluate independently whether it would develop a new, smaller in vitro diagnostic instrument using the Simoa technology for use in clinical lab applications, food quality control testing, and pharmaceutical quality control testing benchtop (the "Feasibility Period") and had the sole right to determine whether or not to develop such a new instrument during the Feasibility Period. If bioMérieux elected to pursue development of such a new instrument, they would have a set number of years to complete development within a specified period, which contains various development milestones which must be accomplished.

bioMérieux received a license to the source and object code of the Company’s Level 1 Data Reduction (L1DR) software. The L1DR software the Company’s proprietary image processing algorithms that convert images of microscopic beads associated with biomarker molecules in microwells. Also, the Company agreed to provide to bioMérieux access to any know how and intellectual property associated with the L1DR software, including any updates and upgrades to the L1DR software during the Feasibility Period. If bioMéreiux exercised its right to develop an instrument independently, this right would continue throughout the development period to the end of the term of the agreement related to independently developed instruments.

It was clarified that the Company can engage a collaboration partner (IVD Partner), subject to restrictions as to the particular parties with which the Company could elect to partner and the assays that can be developed, in the field of in vitro diagnostics used in Clinical Lab Applications. The Company agreed to pay bioMérieux a mid-double-digit percentage of royalties received from the IVD Partner based on assays sales by the IVD Partner.

bioMérieux’s licenses included all patents and know-how owned or controlled by the Company related to the Company’s Simoa technology and upgrades thereto that are necessary for the development, manufacture, use or sale of instruments and assays or consumables on such instruments over the Feasibility Period. If bioMérieux exercised its right to develop an instrument independently, this right would continue throughout the development period to the end of the term of the 2016 Amendment related to independently developed instruments.

bioMérieux retained an option (the Option) to obtain worldwide distribution rights to the HD‑1 floor standing instrument in the applicable fields. The Option was exercisable over a three year period and upon exercise, the Company and bioMérieux were required to negotiate, in good faith, a distribution agreement that would include a specified upfront payment.

The 2016 Amendment included a cash payment of $2.0 million from bioMérieux which was paid in January 2017.

On September 6, 2018, bioMérieux notified the Company that it was terminating the Amended JDLA, forfeiting any future IVD licensing rights to the Company’s Simoa technology and enabling the Company to consolidate and regain control of all Simoa IVD licensing and intellectual property rights.

Accounting assessment

Prior to the execution of the 2016 Amendment, the Company was recognizing revenue over the estimated period of performance of the ongoing units of accounting (Initial Assay Assistance, Benchtop Assistance, and JSC). As a result, the Company recognized $0.2 million and $0.2 million in revenue for the years ended December 31, 2016 and 2015, respectively. At the date of the execution of the 2016 Amendment, the Company had $1.2 million in deferred revenue related to the JDLA. Upon the execution of the 2016 Amendment, all undelivered elements and contingent consideration of the JDLA were cancelled. The Company determined the 2016 Amendment should be accounted for as a modification to the JDLA and the balance of deferred revenue prior to the 2016 Amendment should be included as allocable consideration under the 2016 Amendment resulting in total allocable consideration of $3.2 million. The Company recorded an increase to deferred revenue upon receipt of the $2.0 million during the three months ended March 31, 2017.

The Company has determined that the deliverables included under the 2016 Amendment are rights to the L1DR software, training and rights to future technology improvements for L1DR Software, rights to all future technological improvements related to the Simoa technology, and participation on joint committees.

The Company determined that the L1DR and rights to unspecified technology improvements (the "L1DR Unit of Accounting") includes the sale of software and software related elements and therefore should be accounted for under ASC 985‑605—Software Revenue Recognition. The Company cannot demonstrate Vendor Specific Objective Evidence (VSOE) of fair value for the ongoing obligation to provide unspecified technology improvements. Therefore, the deliverables in the L1DR Unit of Accounting cannot be separated. The Company has applied the combined service approach and the consideration allocated to this unit of accounting is being recognized ratably over the estimated period of performance, which has initially been determined to be estimated to be the three year Feasibility Period. This will be reevaluated each period to determine if there are any changes to the estimated period of performance.

The Company concluded that the rights to future technology improvements for the Simoa technology and the participation on joint committees represented a second unit of accounting (the "Instrument Know How Unit of Accounting"). The deliverables in the Instrument Know How Unit of Accounting are considered non-software deliverables that are subject to ASC 605‑25 and will be delivered over time on a when and if available basis. Revenue is being recognized on a straight line basis over the estimated period of performance, which has initially been determined to be the three year Feasibility Period. This period will be reevaluated each period to determine if there are any changes to the period of performance.

The Option is considered substantive as the Company is at risk with regard to whether bioMérieux will exercise the Option. In addition, the Option exercise payment payable by bioMérieux upon exercise is not priced at a significant and incremental discount. Accordingly, the Option is not considered a deliverable at the inception of the arrangement and the associated Option exercise payment is not included in allocable arrangement consideration.

Under the 2016 Agreement the Company is eligible to receive royalties on net sales of assays sold by bioMérieux in the mid to high single digits, and to receive low double digit royalties on sales of instruments by bioMérieux based on manufactured cost. No royalties have been recognized through December 31, 2019.

Upon termination of the agreement, the Company no longer held an obligation to bioMérieux related to the initial agreement or the amendment to the agreement. As such, the Company immediately recognized all remaining deferred revenue related to the agreements as of the date of termination.

Uman has entered into certain licenses with other companies for use of Uman’s technology. These licenses have royalty components from which the Company earns and recognizes royalty revenue throughout the year. The Company recognized revenue of $0.2 million and $2.1 million for the years ended December 31, 2019 and 2018, respectively, as collaboration revenue.

Evaluation and option agreements and license agreement

In 2015, the Company entered into three agreements, for three separate fields, with a diagnostic company for the evaluation of the Company’s Simoa technology. These agreements each allowed for the option to negotiate a license agreement. In return, the Company received non-refundable payments totaling $2.0 million. In December 2016, the diagnostic company exercised one of its options and the parties entered into a license agreement in one of the fields. This agreement has a one-time non-refundable license fee of $1.0 million and the right to receive running low single digit royalties on licensed products. The negotiation periods for the other two agreements were extended and the negotiations remain ongoing.

For each of the three fields, the right to evaluate the technology, the right to negotiate a license to the technology, and the undelivered license to the technology represents a combined unit of accounting, and the licenses to each of the three fields each have standalone value. The Company has allocated the allocable arrangement consideration based on the relative selling price of each unit of accounting. The best estimated selling price of each of the three options was determined to be representative of the contractual amount paid for each option. The Company defers the amounts allocated to each of the three options until the corresponding license is delivered or, if no license agreement is executed and delivered, when the negotiations for each option terminates.

Upon execution of the license in one of the fields in December 2016, the $1.0 million license fee, in addition to the $0.8 million allocated to the option for this field, resulted in a total of $1.8 million of consideration being recognized as revenue as there were no remaining undelivered performance obligations. Because the negotiations remain ongoing with respect to the other two fields, the consideration allocated to these options of $1.2 million has been deferred and is recorded as deferred revenue as of December 31, 2019.

In December 2018 the Company entered into an option agreement for the rights to negotiate an exclusive agreement with the diagnostic company. In exchange for the rights to negotiate an exclusive agreement, the Company will receive $0.5 million in consideration. As the right to negotiate with the Company has not been executed, the consideration from this agreement is deferred until the sooner of the execution of the contract or the end of the option period. As the option has not been exercised as of December 31, 2019, the $0.5 million is recorded as deferred revenue.

As of December 31, 2019 the Company has $1.7 million of deferred revenue related to ongoing negotiations with the diagnostics company.

Employee benefit-plans	12 Months Ended
Employee benefit-plans	Dec. 31, 2019
Employee benefit plans
Employee benefit plans	14. Employee benefit-plans The Company sponsors a 401(k) savings plan for employees. The Company may make discretionary contributions for each 401(k) plan year. During the years ended December 31, 2019 and 2018 the Company made contributions of $0.5 million and $0.1 million, respectively. During the year ended December 31, 2017, the Company did not make any contributions.

Business combinations

12 Months Ended

Dec. 31, 2019

Business combinations

Business combinations

15. Business combinations

Aushon BioSystems,Inc.

On January 30, 2018, the Company completed the acquisition of Aushon pursuant to an Agreement and Plan of Merger dated January 30, 2018. The Company acquired Aushon to complement its existing product line, improve its existing research and development capabilities in assay development and software engineering, and expand its customer base. The acquisition of Aushon was accounted for as a business combination and the Company has recorded the assets acquired and liabilities assumed at their respective fair values as of the acquisition date.

In connection with the closing of the acquisition of Aushon, the Company paid $3.2 million at closing, and an additional $0.8 million in July 2018, the six-month anniversary of the acquisition date.

The following table presents the allocation of the purchase consideration for the transaction as of January 30, 2018 including the allocation of the purchase consideration (in thousands):


Fair value of consideration transferred:
Cash	$	3,200
Obligation to issue cash		800
Total acquisition consideration	$	4,000

Fair value of assets acquired and liabilities assumed:
Cash and cash equivalents	$	199
Accounts receivable		210
Inventory		828
Prepaid expenses		71
Property and equipment and other non-current assets		180
Intangible Assets		2,950
Goodwill		1,308
Total assets acquired		5,746
Contractual obligations		(1,155)
Accounts payable and accrued liabilities		(591)
Net assets acquired	$	4,000

The intangible assets identified in the purchase price allocation discussed above include developed technology, tradenames and customer relationships. Tradenames are amortized over the useful life on a straight-line basis, while developed technology and customer relationships are amortized over their respective useful lives on an accelerated basis reflecting the period of expected derived benefits of the underlying assets. Developed technology consists of products that have reached technological feasibility and trade names represent acquired company and product names. To value the developed technology and trade name assets, the Company utilized a relief from royalty method. Under the methodology, fair value is calculated as the discounted cash flow savings accruing to the owner for not having to pay the royalty. Key assumptions included expected revenue attributable to the assets, royalty rates, discount rate and estimated asset lives. Customer relationships represent the underlying relationships with certain customers to provide ongoing services and continued product sale opportunities. The Company utilized excess earnings methodology to derive the fair value of the customer relationships. Key assumptions included expected attrition of customer's rates, operating income margins and discount rate. The Company used a risk-adjusted discount rate of 14.4% in determining the fair value of the intangible assets.

The goodwill recorded as a result of the acquisition of Aushon represents the strategic benefits of growing the Company's product portfolio and the expected revenue growth from increased market penetration from future products and customers. None of the goodwill recorded is tax deductible for income tax purposes.

The Company incurred a total of $0.1 million in transaction costs in connection with the transaction, which were included in selling, general and administrative expense within the consolidated statement of operations for the year ended December 31, 2018.

UmanDiagnostics AB

On August 1, 2019, the Company completed its acquisition of Uman for an aggregate purchase price of $21.2 million, comprised of (i) $15.7 million in cash plus (ii) 191,152 shares of common stock (representing $5.5 million based on the closing prices of the Company’s common stock on the Nasdaq Global Market on July 1, 2019 and August 1, 2019, the dates of issuance). The acquisition of Uman closed with respect to 95% of the outstanding shares of capital stock of Uman on July 1, 2019 and with respect to the remaining 5% of the outstanding shares of capital stock of Uman on August 1, 2019.

Uman supplies Nf-L antibodies and ELISA kits, which are widely recognized by researchers and biopharmaceutical and diagnostics companies world-wide as the premier solution for the detection of Nf-L to advance the development of therapeutics and diagnostics for neurodegenerative conditions. With the acquisition of Uman, the Company has secured a long-term source of supply for a critical technology. This acquisition was considered a business acquisition for accounting purposes.

The Company has accounted for the acquisition of Uman as a purchase of a business under U.S. GAAP. Under the acquisition method of accounting, the assets and liabilities of Uman are recorded as of the acquisition date of July 1, 2019, at their respective fair values, and consolidated with those of the Company.

The Company has preliminarily allocated the purchase price to the net tangible and intangible assets based on their estimated fair values as of July 1, 2019. As such, the fair value of the assets acquired and liabilities assumed, including intangible assets, presented in the table below are provisional and will be finalized in a later period once the fair value procedures are completed. Goodwill established as a result of the Uman acquisition is not tax deductible in any taxing jurisdiction.

The following table summarizes the preliminary purchase price allocation, net of $1.2 million in cash and cash equivalents acquired (in thousands):


Purchase price:
Cash and stock paid	$	21,217
Cash and cash equivalents acquired		1,221
Purchase price, net		19,996

Assets (liabilities) acquired:
Accounts receivable	$	638
Inventory		1,680
Prepaids and other current assets		114
Property and equipment		33
Intangibles		13,450
Goodwill		8,111
Accounts payable		(20)
Accrued expense and other current liabilities		(871)
Deferred tax liabilities		(3,139)
Total	$	19,996

Revenue and net income related to Uman’s operations were $1.1 million and less than $0.1 million, respectively, for the six months following the July 1, 2019 acquisition date, and is included in the Company’s consolidated statements of operations for the year ended December 31, 2019.

The following unaudited pro forma information presents the condensed consolidated results of operations of the Company and Uman for the years ended December 31, 2019 and 2018 as if the acquisition of Uman had been completed on January 1, 2018. These pro forma condensed consolidated financial results have been prepared for comparative purposes only and include certain adjustments that reflect pro forma results of operations, such as increased amortization for the fair value of acquired intangible assets, increased cost of sales related to the inventory valuation adjustment, and adjustments relating to the tax effect of combining the Company and Uman businesses.

The unaudited pro forma results do not reflect any operating efficiencies or potential cost savings which may result from the consolidation of the operations of the Company and Uman. Accordingly, these unaudited pro forma results are presented for informational purposes only and are not necessarily indicative of the results of operations that actually would have been achieved had the acquisition occurred as of January 1, 2018, nor are they intended to represent or be indicative of future results of operations (in thousands):


	Years ended December 31,
	2019		2018
Revenue (unaudited)	$	57,597	$	38,753
Pre-tax loss (unaudited)	$	(38,636)	$	(33,894)

During the year ended December 31, 2019, the Company incurred $1.9 million in costs associated with the acquisition of Uman. Costs associated with the acquisition of Uman are recorded as selling, general, and administrative expenses within the consolidated statements of operations.

Goodwill and Acquired Intangible Assets

12 Months Ended

Dec. 31, 2019

Goodwill and Acquired Intangible Assets

Goodwill and Acquired Intangible Assets

16. Goodwill and intangible assets

As of December 31, 2019 the carrying amount of goodwill was $9.4 million. The following is a rollforward of the Company’s goodwill balance (in thousands):


	Goodwill
Balance as of December 31, 2018	$	1,308
Goodwill acquired		8,111
Cumulative translation adjustment		(66)
Balance as of December 31, 2019	$	9,353

Acquired intangible assets consist of the following (dollars in thousands):


		December 31, 2019
		Gross				Cumulative		Net		Weighted
	Estimated Useful	Carrying		Accumulated		Translation		Carrying		Average
	Life (in years)	Value		Amortization		Adjustment		Value		Life Remaining
Know-how	8.5	$	13,000	$	(767)	$	(99)	$	12,134	8.00
Developed technology	7		1,650		(737)		—		913	5.09
Customer relationships	8.5 - 10		1,360		(421)		(1)		938	8.08
Non-compete agreements	5.5		340		(34)		(2)		304	5.00
Trade names	3		50		(32)		—		18	1.09
Total		$	16,400	$	(1,991)	$	(102)	$	14,307


		December 31, 2018
		Gross				Cumulative		Net		Weighted
	Estimated Useful	Carrying		Accumulated		Translation		Carrying		Average
	Life (in years)	Value		Amortization		Adjustment		Value		Life Remaining
Developed technology	7	$	1,650	$	(378)	$	—	$	1,272	6.08
Customer relationships	10		1,250		(209)		—		1,041	9.08
Trade names	3		50		(15)		—		35	2.08
Total		$	2,950	$	(602)	$	—	$	2,348

The Company acquired $13.5 million of intangible assets in the Uman acquisition, of which $13.0 million was assigned to know-how, $0.4 million was assigned to non-compete agreements, and $0.1 million was assigned to customer relationships. The know-how and customer relationships intangible assets are being amortized on a straight-line basis over an 8.5 year amortization period, and the non-compete agreement intangible asset is being amortized on a straight-line basis over a 5.5 year amortization period. In total, the weighted-average amortization period for these intangible assets is 8.4 years.

The Company is currently evaluating the fair value of assets acquired and liabilities assumed from the Uman acquisition, including intangible assets and their related amortization periods. As such, the $13.5 million in intangible assets presented in the table above are provisional and will be finalized in a later period once the fair value procedures are completed.

Know-how consists of the processes and procedures to produce Uman’s products. Customer relationships represent the underlying relationships with certain customers to provide continued product sale opportunities. The Company utilized excess earnings methodology to derive the fair value of the customer relationships. The Company is currently evaluating the fair value of assets acquired and liabilities assumed from the Uman acquisition, including intangible assets and their related amortization periods.

The Company recorded amortization expense of $1.4 million and $0.6 million for the years ended December 31, 2019 and 2018, respectively. No amortization expense was recognized in the year ended December 31, 2017 as the intangible assets are a result of the purchase of Aushon in January 2018 and Uman in July 2019. Amortization of developed technology is recorded within research and development expenses, amortization of customer relationships is recorded within selling, general, and administrative expenses, amortization of trade names is recorded within selling, general, and administrative expenses, amortization of non-compete agreements is recorded within selling, general, and administrative expenses, and amortization of know-how is recorded within cost of goods sold.

Future estimated amortization expense of acquired intangible assets as of December 31, 2019 is as follows (amounts in thousands):


For the Years Ended December 31,	Estimated Amortization Expense
2020	$	2,110
2021		2,013
2022		1,930
2023		1,848
2024		1,733
Thereafter		4,673
	$	14,307

Related party transactions	12 Months Ended
Related party transactions	Dec. 31, 2019
Related party transactions
Related party transactions	17. Related party transactions bioMérieux is a customer through its Joint Development and License Agreement and also a holder of the Company’s common stock. bioMérieux formerly also had a designee on the Company’s Board of Directors. On September 6, 2018, bioMérieux notified the Company that it was terminating the Amended JDLA. The termination of the agreement resulted in the immediate recognition of the remaining deferred revenue. The Company recognized revenue from bioMérieux related to the Amended JDLA of less than $0.1 million, $2.1 million, and $1.1 million in the years ended December 31 2019, 2018, and 2017, respectively. As described in Note 9, in June 2007, the Company entered into a license agreement for certain intellectual property with Tufts. Tufts is a related party to the Company due to Tuft’s equity ownership in the Company and because a board member of the Company’s Board of Directors was affiliated with Tufts. During the years ended December 31, 2019, 2018, and 2017 the Company recorded royalty expense of $1.0 million, $0.7 million, and $0.5 million, respectively, in cost of product revenue on the consolidated statements of operations. During the year ended December 31, 2017, Harvard University became a related party because a member of the Company’s Board of Directors is affiliated with Harvard University. Revenue recorded from sales to Harvard University was $0.1 million for the year ended December 31, 2019, and less than $0.1 million for each of the years ended December 31, 2018 and December 31, 2017. On November 28, 2018, the Company entered into a sponsor agreement with Powering Precision Health (PPH), a 501(c)6 not-for-profit entity of which an executive of the Company is a board member, through December 31, 2018. The agreement committed a maximum of $120,000 in funds and services to be provided to PPH for the term of the agreement. On November 14, 2019, the Company entered into the first amendment to the PPH sponsorship agreement. The agreement amended the $120,000 annual committed maximum amount to $200,000 for the annual committed amount. The agreement is terminable by either party and does not bind the Company to beyond the term of the agreement. For the years ended December 31, 2019 and 2018, the Company had total contributions of $0.1 million and less than $0.1 million, respectively.

Restricted Cash	12 Months Ended
Restricted Cash	Dec. 31, 2019
Restricted Cash
Restricted Cash	18. Restricted cash The Company’s restricted cash consists of cash that the Company is contractually obligated to maintain in accordance the terms of the Letter of Credit in the lease agreement. The $1.0 million Letter of Credit drawable by the lessor under specifically outlined conditions within the lease, which are primarily related to rent payments. The amount of the Letter of Credit will be reduced at 41 and 65 months after the commencement date of the lease to $750,000 and then $250,000, respectively. The Company had $1.0 million of restricted cash as of December 31, 2019 and 2018, respectively.

Quarterly Data (Unaudited)

12 Months Ended

Dec. 31, 2019

Quarterly Data (Unaudited)

Quarterly Data (Unaudited)

19. Quarterly data (Unaudited)

(Amounts in thousands, except share and per share data)


2019	Q1		Q2		Q3		Q4		Total Year
Product revenue	$	9,547	$	8,776	$	10,737	$	11,431	$	40,491
Service and other revenue		2,790		4,760		4,207		4,302		16,059
Collaboration and license revenue		—		—		—		184		184
Total revenue		12,337		13,536		14,944		15,917		56,734
Costs of goods sold:
Cost of product revenue		4,248		4,455		5,513		6,684		20,900
Cost of services and other revenue		2,082		2,150		2,398		2,368		8,998
Total costs of goods sold and services		6,330		6,605		7,911		9,052		29,898
Gross profit		6,007		6,931		7,033		6,865		26,836
Operating expenses:
Research and development		3,852		4,016		3,924		4,398		16,190
Selling, general and administrative		11,512		13,429		13,352		13,953		52,246
Total operating expenses		15,364		17,445		17,276		18,351		68,436
Loss from operations		(9,357)		(10,514)		(10,243)		(11,486)		(41,600)
Interest income (expense), net		21		42		282		282		627
Other income (expense), net		(47)		(68)		(34)		139		(10)
Income tax benefit (provision)		(22)		(23)		125		107		187
Net loss	$	(9,405)	$	(10,563)	$	(9,870)	$	(10,958)	$	(40,796)
Net loss per share, basic and diluted	$	(0.42)	$	(0.46)	$	(0.37)	$	(0.39)	$	(1.63)
Weighted-average common shares outstanding, basic and diluted		22,422,960		23,213,653		26,627,831		28,021,957		25,090,708


2018	Q1		Q2		Q3		Q4		Total Year
Product revenue	$	4,745	$	5,200	$	5,962	$	7,458	$	23,365
Service and other revenue		2,507		3,174		3,017		3,419		12,117
Collaboration and license revenue		269		269		1,612		—		2,150
Total revenue		7,521		8,643		10,591		10,877		37,632
Costs of goods sold:
Cost of product revenue		2,773		2,945		3,277		3,734		12,729
Cost of services and other revenue		1,576		1,725		1,719		1,935		6,955
Total costs of goods sold and services		4,349		4,670		4,996		5,669		19,684
Gross profit		3,172		3,973		5,595		5,208		17,948
Operating expenses:
Research and development		3,644		3,705		4,411		4,045		15,805
Selling, general and administrative		6,691		7,579		8,846		10,577		33,693
Total operating expenses		10,335		11,284		13,257		14,622		49,498
Loss from operations		(7,163)		(7,311)		(7,662)		(9,414)		(31,550)
Interest income (expense), net		(24)		16		30		24		46
Other income (expense), net		(15)		(48)		(25)		81		(7)
Income tax benefit (provision)		—		—		—		(25)		(25)
Net loss	$	(7,202)	$	(7,343)	$	(7,657)	$	(9,334)	$	(31,536)
Net loss per share, basic and diluted	$	(0.33)	$	(0.34)	$	(0.35)	$	(0.42)	$	(1.43)
Weighted-average common shares outstanding, basic and diluted		21,788,605		21,890,978		22,670,786		22,221,305		21,994,317

Subsequent events	12 Months Ended
Subsequent events	Dec. 31, 2019
Subsequent events
Subsequent events	20. Subsequent events The Company had no significant subsequent events for the period December 31, 2019 through the filing date of this Annual Report on Form 10-K.

Significant accounting policies (Policies)

12 Months Ended

Dec. 31, 2019

Significant accounting policies

Principles of consolidation

Use of estimates

Revenue recognition

Customers

Product revenue

Service and other revenue

Collaboration and license revenue

Payment terms

Disaggregated Revenue


	Year Ended
	December 31, 2019
(in thousands)	NA		EMEA		Asia Pacific		Total
Product revenues
Instruments	$	6,250	$	5,243	$	3,393	$	14,886
Consumable and other products		14,148		9,674		1,783		25,605
Totals	$	20,398	$	14,917	$	5,176	$	40,491

Service and other revenues
Service-type warranties	$	3,139	$	1,323	$	171	$	4,633
Research services		8,845		704		456		10,005
Other services		825		565		31		1,421
Totals	$	12,809	$	2,592	$	658	$	16,059

Collaboration and license revenue
Collaboration and license revenue	$	167	$	17	$	—	$	184
Totals	$	167	$	17	$	—	$	184

Changes in deferred revenue from contracts with customers were as follows (in thousands):


	Year Ended December 31, 2019
Balance at December 31, 2018	$	5,957
606 adoption adjustment		(86)
Deferral of revenue		3,925
Recognition of deferred revenue		(4,633)
Balance at December 31, 2019	$	5,163

Costs to obtain a contract


	Year Ended December 31, 2019
Balance at December 31, 2018	$	—
606 adoption adjustment		307
Deferral of costs to obtain a contract		848
Recognition of costs to obtain a contract		(820)
Balance at December 31, 2019	$	335

ASC 606 provides entities with certain practical expedients and accounting policy elections to minimize the cost and burden of adoption.

The Company will exclude from its transaction price any amounts collected from customers related to sales and other similar taxes.

Business combinations

Cost of revenue

Cost of license revenue, related party consists of license fees that are the direct results of cash payments received related to license agreements.

Research and development expenses

Selling, general, and administrative expense

Selling, general, and administrative expenses

Net loss per share


	Year Ended December 31,
	2019	2018	2017
Unvested restricted common stock and restricted stock units	409,929	361,468	177,192
Outstanding stock options	2,507,062	2,476,911	2,249,843
Outstanding common stock warrants	10,000	76,041	86,090
Total	2,926,991	2,914,420	2,513,125

Cash and Cash equivalents

Cash and cash equivalents


	As of
	December 31,
	2019		2018
Cash	$	6,406	$	1,821
Money market funds invested in U.S. Treasury obligations		102,749		42,608
Total cash and cash equivalents	$	109,155	$	44,429

Restricted cash and deposits

Accounts Receivable and allowance for doubtful accounts

Accounts receivable and allowance for doubtful accounts

Inventory

Property and equipment


Laboratory and manufacturing equipment		Five years
Computers and software		Three years
Office furniture and equipment		Seven years
Leasehold improvements		Shorter of the useful life of the asset or the remaining term of the lease

Software development costs

Investments

Fair value of financial instruments

Level 1 inputs are quoted prices (unadjusted) in active markets for identical assets or liabilities.

Level 2 inputs are inputs other than quoted prices that are observable for the asset or liability, either directly or indirectly; and

Level 3 inputs are unobservable inputs that reflect the Company’s own assumptions about the assumptions market participants would use in pricing the asset or liability.

Fair value measurements as of December 31, 2019 are as follows (in thousands):


			Quoted prices				Significant
			in active		Significant other		unobservable
			markets		observable		inputs
Description	Total		(Level 1)		inputs (Level 2)		(Level 3)
Financial assets
Cash equivalents	$	109,155	$	109,155	$	—	$	—
Note receivable		150		—		—		150
	$	109,305	$	109,155	$	—	$	150

Fair value measurements as of December 31, 2018 are as follows (in thousands):


			Quoted prices				Significant
			in active		Significant other		unobservable
			markets		observable		inputs
Description	Total		(Level 1)		inputs (Level 2)		(Level 3)
Financial assets
Cash equivalents	$	42,608	$	42,608	$	—	$	—
Note receivable		150		—		—		150
	$	42,758	$	42,608		—	$	150

Warranties

Income taxes

Credit, product and supplier concentrations and off-balance-sheet risk

Customers outside the United States represented 50% and 40% of the Company’s gross trade accounts receivable balance as of December 31, 2019 and 2018, respectively.

Stock-based compensation


	Year Ended December 31,
	2019	2018	2017
Risk-free interest rate	1.4% - 2.6%	2.6% - 3.0%	1.8% - 2.1%
Expected dividend yield	None	None	None
Expected term (in years)	6.0	5.9	6.0
Expected volatility	33.5% - 39.7%	32.4% - 36.8%	46.0% - 52.0%

Recent accounting pronouncements

The Company's consolidated financial statements for the prior-year period have not been revised and are reflective of the revenue recognition requirements which were in effect for that period.

The Company recorded an adjustment to the accumulated deficit of $0.4 million as of January 1, 2019 for the cumulative effect primarily related to the deferral of sales commissions.


											Prior to
											adoption of
	As				Adjusted under		As reported				ASC 606
	reported				ASC 606		December 31,				December 31,
	December 31, 2018		Adjustments		January 1, 2019		2019		Adjustments		2019
Assets:
Accounts receivable	$	6,792	$	47	$	6,839	$	10,906	$	—	$	10,906
Prepaid expenses and other current assets		2,330		288		2,618		2,137		335		1,802
Other non-current assets		536		19		555		557		—		557

Liabilities:
Deferred revenue		5,437		43		5,394		4,697		(209)		4,488
Deferred revenue, net of current portion		520		43		477		466		14		480

Stockholders’ equity:
Accumulated deficit	$	(175,888)	$	(440)	$	(175,448)	$	(216,244)	$	(140)	$	(216,104)


	For the Year Ended December 31, 2019
					Under ASC
	Under ASC 606		Adjustment		605
Product revenue	$	40,491	$	55	$	40,546
Service revenue		16,059		273		16,332
Costs of goods sold and services		29,898		1		29,899
Gross profit		26,836		327		27,163
Selling general and administrative expenses		52,246		27		52,273
Net loss	$	(40,796)	$	300	$	(40,496)

Significant accounting policies (Tables)

12 Months Ended

Dec. 31, 2019

Revenue recognition

Schedule of disaggregated revenue


	Year Ended
	December 31, 2019
(in thousands)	NA		EMEA		Asia Pacific		Total
Product revenues
Instruments	$	6,250	$	5,243	$	3,393	$	14,886
Consumable and other products		14,148		9,674		1,783		25,605
Totals	$	20,398	$	14,917	$	5,176	$	40,491

Service and other revenues
Service-type warranties	$	3,139	$	1,323	$	171	$	4,633
Research services		8,845		704		456		10,005
Other services		825		565		31		1,421
Totals	$	12,809	$	2,592	$	658	$	16,059

Collaboration and license revenue
Collaboration and license revenue	$	167	$	17	$	—	$	184
Totals	$	167	$	17	$	—	$	184

Schedule of changes in deferred revenue from contracts with customers

Changes in deferred revenue from contracts with customers were as follows (in thousands):


	Year Ended December 31, 2019
Balance at December 31, 2018	$	5,957
606 adoption adjustment		(86)
Deferral of revenue		3,925
Recognition of deferred revenue		(4,633)
Balance at December 31, 2019	$	5,163

Schedule of costs to obtain a contract

The change in the balance of costs to obtain a contract are as follows (in thousands):


	Year Ended December 31, 2019
Balance at December 31, 2018	$	—
606 adoption adjustment		307
Deferral of costs to obtain a contract		848
Recognition of costs to obtain a contract		(820)
Balance at December 31, 2019	$	335

Schedule of outstanding potentially dilutive securities that have been excluded in the calculation of diluted net loss per share


	Year Ended December 31,
	2019	2018	2017
Unvested restricted common stock and restricted stock units	409,929	361,468	177,192
Outstanding stock options	2,507,062	2,476,911	2,249,843
Outstanding common stock warrants	10,000	76,041	86,090
Total	2,926,991	2,914,420	2,513,125

Schedule of cash and cash equivalents

Cash and cash equivalents consist of the following (in thousands):


	As of
	December 31,
	2019		2018
Cash	$	6,406	$	1,821
Money market funds invested in U.S. Treasury obligations		102,749		42,608
Total cash and cash equivalents	$	109,155	$	44,429

Schedule of estimated useful lives


Laboratory and manufacturing equipment		Five years
Computers and software		Three years
Office furniture and equipment		Seven years
Leasehold improvements		Shorter of the useful life of the asset or the remaining term of the lease

Schedule of fair value measurements

Fair value measurements as of December 31, 2019 are as follows (in thousands):


			Quoted prices				Significant
			in active		Significant other		unobservable
			markets		observable		inputs
Description	Total		(Level 1)		inputs (Level 2)		(Level 3)
Financial assets
Cash equivalents	$	109,155	$	109,155	$	—	$	—
Note receivable		150		—		—		150
	$	109,305	$	109,155	$	—	$	150

Fair value measurements as of December 31, 2018 are as follows (in thousands):


			Quoted prices				Significant
			in active		Significant other		unobservable
			markets		observable		inputs
Description	Total		(Level 1)		inputs (Level 2)		(Level 3)
Financial assets
Cash equivalents	$	42,608	$	42,608	$	—	$	—
Note receivable		150		—		—		150
	$	42,758	$	42,608		—	$	150

Summary of fair value assumptions of stock options granted to employees and directors for their services on the Company’s Board of Directors


	Year Ended December 31,
	2019	2018	2017
Risk-free interest rate	1.4% - 2.6%	2.6% - 3.0%	1.8% - 2.1%
Expected dividend yield	None	None	None
Expected term (in years)	6.0	5.9	6.0
Expected volatility	33.5% - 39.7%	32.4% - 36.8%	46.0% - 52.0%

ASU 2014-09

Revenue recognition

Schedule of impact on consolidated balance sheet and statement of operations due to adoption of ASU 606


											Prior to
											adoption of
	As				Adjusted under		As reported				ASC 606
	reported				ASC 606		December 31,				December 31,
	December 31, 2018		Adjustments		January 1, 2019		2019		Adjustments		2019
Assets:
Accounts receivable	$	6,792	$	47	$	6,839	$	10,906	$	—	$	10,906
Prepaid expenses and other current assets		2,330		288		2,618		2,137		335		1,802
Other non-current assets		536		19		555		557		—		557

Liabilities:
Deferred revenue		5,437		43		5,394		4,697		(209)		4,488
Deferred revenue, net of current portion		520		43		477		466		14		480

Stockholders’ equity:
Accumulated deficit	$	(175,888)	$	(440)	$	(175,448)	$	(216,244)	$	(140)	$	(216,104)


	For the Year Ended December 31, 2019
					Under ASC
	Under ASC 606		Adjustment		605
Product revenue	$	40,491	$	55	$	40,546
Service revenue		16,059		273		16,332
Costs of goods sold and services		29,898		1		29,899
Gross profit		26,836		327		27,163
Selling general and administrative expenses		52,246		27		52,273
Net loss	$	(40,796)	$	300	$	(40,496)

Inventory (Tables)

12 Months Ended

Dec. 31, 2019

Inventory

Summary of inventory

Inventory consists of the following (in thousands):


	As of
	December 31,
	2019		2018
Raw materials	$	4,717	$	1,546
Work in process		2,573		2,331
Finished goods		3,173		2,068
Total	$	10,463	$	5,945

Property and equipment (Tables)

12 Months Ended

Dec. 31, 2019

Property and equipment

Schedule of Property and equipment

Property and equipment consists of the following (in thousands):


	As of
	December 31,
	2019		2018
Laboratory and manufacturing equipment	$	5,391	$	4,127
Office furniture and equipment		1,403		789
Computers and software		1,103		786
Leasehold improvements		8,489		244
		16,386		5,946
Less: accumulated depreciation		(4,339)		(3,023)
Total	$	12,047	$	2,923

Other accrued expenses (Tables)

12 Months Ended

Dec. 31, 2019

Other accrued expenses

Summary of other accrued expenses

Other accrued expenses consist of the following (in thousands):


	As of December 31,
	2019		2018
Accrued inventory	$	459	$	599
Accrued royalties		476		323
Accrued professional services		655		723
Accrued development costs		151		795
Accrued other		757		689
Total accrued expenses	$	2,498	$	3,129

Summary of other non-current liabilities

Other non-current liabilities consist of the following (in thousands):


	As of December 31,
	2019		2018
Leasehold obligation incentive	$	7,572	$	—
Deferred rent		3,009		265
Deferred tax liabilities		2,825		7
Other		1		6
Total non-current liabilities	$	13,407	$	278

Income taxes (Tables)

12 Months Ended

Dec. 31, 2019

Income taxes

Schedule of components of income (loss) before income taxes


	Year Ended December 31,
	2019		2018		2017
United States	$	(40,010)	$	(31,436)	$	(27,019)
Foreign		(973)		(75)		—
	$	(40,983)	$	(31,511)	$	(27,019)

Schedule of provision for (benefit from) income taxes


	Year Ended
	December 31,
	2019		2018		2017
Current:
United States
Federal	$	—	$	—	$	—
State		(20)		(18)		—
Foreign		(93)		—		—
Total current income tax provision		(113)		(18)		—
Deferred
United States
Federal		(3)		(2)		—
State		(1)		(5)		—
Foreign		304		—		—
Total deferred income tax benefit (provision)		300		(7)		—
Total income tax benefit (provision)	$	187	$	(25)	$	—

Schedule of reconciliation of the federal statutory income tax rate to the effective tax rate


	Year Ended December 31,
	2019		2018
Federal statutory income tax rate	21.0	%	21.0	%
Foreign tax rate differential	—	%	—	%
State taxes, net of federal benefit	3.2	%	6.0	%
Tax credits	2.3	%	2.7	%
Share-based compensation	2.3	%	1.1	%
Permanent items	(0.9)	%	(1.2)	%
Defereed tax rate changes	(1.4)	%	—	%
Change in valuation allowance	(24.6)	%	(29.9)	%
Other	(1.4)	%	0.2	%
Effective income tax rate	0.5	%	(0.1)	%

Schedule of deferred tax assets and liabilities


	December 31,
	2019		2018
Deferred tax assets:
Net operating loss carryforwards	$	43,814	$	35,623
Tax credits		5,518		4,678
Deferred revenue		1,247		1,614
Depreciation		—		86
Amortization		928		792
Stock-based compensation		973		541
Deferred Rent		727		—
Lease incentive obligation		1,828		—
Other deferred tax assets		1,325		1,378
Total deferred tax assets		56,360		44,712
Less: Valuation allowances		(54,137)		(44,033)
Net deferred tax assets		2,223		679
Deferred tax liabilities:
Section 481(a) adjustment - accrued bonus		—		(59)
Depreciation		(1,769)		—
Amortization of acquired intangibles		(3,031)		(610)
Inventory		(212)		—
Goodwill		(31)		(17)
Other deferred tax liabitlies		(5)		—
Net deferred tax assets (liabilities)	$	(2,825)	$	(7)

Common Stock, warrants, stock-based compensation, stock options, restricted stock and restricted stock units (Tables)

12 Months Ended

Dec. 31, 2019

Common Stock, warrants, stock-based compensation, stock options, restricted stock and restricted stock units

Schedule of common stock reserved


	As of December 31,
	2019	2018
Common stock warrants	10,000	76,041
Common stock options and unvested restricted common stock	2,916,991	2,838,402
Shares reserved for future awards under compensation plan	882,715	2,433,999
	3,809,706	5,348,442

Summary of warrant activity


		Weighted
	Issued and	Average
	exercisable	Exercise Price
As of December 31, 2018	76,041	$	10.10
Issued	—
Exercised	(66,041)		10.90
Cancelled	—
As of December 31, 2019	10,000	$	4.83

Summary of share-based compensation expense for all stock awards


	December 31,
	2019		2018		2017
Cost of product revenue	$	86	$	55	$	24
Cost of service and other revenue		238		173		52
Research and development		718		513		180
Selling, general, and administrative		5,346		4,143		1,912
Total	$	6,388	$	4,884	$	2,168

Summary of stock option activity


		Weighted-average		Remaining contractual	Aggregate intrinsic value
	Options	exercise price		life (in years)	(in thousands)
Outstanding at December 31, 2018	2,476,911	$	9.65	7.73	$	22,108
Granted	882,959	$	24.20
Exercised	(414,672)	$	6.80
Cancelled	(438,136)	$	14.37
Outstanding at December 31, 2019	2,507,062	$	14.41	7.58	$	24,870
Vested and expected to vest at December 31, 2019	2,507,062	$	14.41	7.58	$	24,870
Exercisable at December 31, 2019	1,284,900	$	8.70	6.46	$	19,239

Summary of restricted stock units activity


		Weighted-average
		grant date
		fair value
	Shares	per share
Unvested RSUs as of December 31, 2018	321,662	$	15.84
Granted	246,588	$	24.22
Vested	(136,062)	$	17.11
Cancelled	(62,065)	$	18.82
Unvested RSUs as of December 31, 2019	370,123	$	20.48

Commitments and contingencies (Tables)

12 Months Ended

Dec. 31, 2019

Commitments and contingencies

Schedule of minimum future rent payments under the lease agreement

As of December 31, 2019, the minimum future rent payments under the lease agreements are as follows (in thousands):


2020	$	2,081
2021		3,322
2022		3,396
2023		3,480
2024 and Forward		25,760
	$	38,039

Long term debt (Tables)

12 Months Ended

Dec. 31, 2019

Long Term Debt

Schedule of debt payment obligations due based on principal payments

As of December 31, 2019, debt payment obligations due based on principal payments are as follows (in thousands):


2020	$	—
2021		7,688
	$	7,688

Business combinations (Tables)

12 Months Ended

Dec. 31, 2019

Aushon acquisition

Schedule of fair value of consideration transferred

The following table presents the allocation of the purchase consideration for the transaction as of January 30, 2018 including the allocation of the purchase consideration (in thousands):


Fair value of consideration transferred:
Cash	$	3,200
Obligation to issue cash		800
Total acquisition consideration	$	4,000

Fair value of assets acquired and liabilities assumed:
Cash and cash equivalents	$	199
Accounts receivable		210
Inventory		828
Prepaid expenses		71
Property and equipment and other non-current assets		180
Intangible Assets		2,950
Goodwill		1,308
Total assets acquired		5,746
Contractual obligations		(1,155)
Accounts payable and accrued liabilities		(591)
Net assets acquired	$	4,000

UmanDiagnostics AB Acquisition

Schedule of fair value of consideration transferred

The following table summarizes the preliminary purchase price allocation, net of $1.2 million in cash and cash equivalents acquired (in thousands):


Purchase price:
Cash and stock paid	$	21,217
Cash and cash equivalents acquired		1,221
Purchase price, net		19,996

Assets (liabilities) acquired:
Accounts receivable	$	638
Inventory		1,680
Prepaids and other current assets		114
Property and equipment		33
Intangibles		13,450
Goodwill		8,111
Accounts payable		(20)
Accrued expense and other current liabilities		(871)
Deferred tax liabilities		(3,139)
Total	$	19,996

Schedule of fair value of assets acquired and liabilities assumed


	Years ended December 31,
	2019		2018
Revenue (unaudited)	$	57,597	$	38,753
Pre-tax loss (unaudited)	$	(38,636)	$	(33,894)

Goodwill and Acquired Intangible Assets (Tables)

12 Months Ended

Dec. 31, 2019

Goodwill and Acquired Intangible Assets

Rollforward of goodwill balance

The following is a rollforward of the Company’s goodwill balance (in thousands):


	Goodwill
Balance as of December 31, 2018	$	1,308
Goodwill acquired		8,111
Cumulative translation adjustment		(66)
Balance as of December 31, 2019	$	9,353

Summary of intangible assets

Acquired intangible assets consist of the following (dollars in thousands):


		December 31, 2019
		Gross				Cumulative		Net		Weighted
	Estimated Useful	Carrying		Accumulated		Translation		Carrying		Average
	Life (in years)	Value		Amortization		Adjustment		Value		Life Remaining
Know-how	8.5	$	13,000	$	(767)	$	(99)	$	12,134	8.00
Developed technology	7		1,650		(737)		—		913	5.09
Customer relationships	8.5 - 10		1,360		(421)		(1)		938	8.08
Non-compete agreements	5.5		340		(34)		(2)		304	5.00
Trade names	3		50		(32)		—		18	1.09
Total		$	16,400	$	(1,991)	$	(102)	$	14,307


		December 31, 2018
		Gross				Cumulative		Net		Weighted
	Estimated Useful	Carrying		Accumulated		Translation		Carrying		Average
	Life (in years)	Value		Amortization		Adjustment		Value		Life Remaining
Developed technology	7	$	1,650	$	(378)	$	—	$	1,272	6.08
Customer relationships	10		1,250		(209)		—		1,041	9.08
Trade names	3		50		(15)		—		35	2.08
Total		$	2,950	$	(602)	$	—	$	2,348

Schedule of future estimated amortization expense of acquired intangible assets

Future estimated amortization expense of acquired intangible assets as of December 31, 2019 is as follows (amounts in thousands):


For the Years Ended December 31,	Estimated Amortization Expense
2020	$	2,110
2021		2,013
2022		1,930
2023		1,848
2024		1,733
Thereafter		4,673
	$	14,307

Quarterly Data (Unaudited) (Tables)

12 Months Ended

Dec. 31, 2019

Quarterly Data (Unaudited)

Quarterly Data (Unaudited)

(Amounts in thousands, except share and per share data)


2019	Q1		Q2		Q3		Q4		Total Year
Product revenue	$	9,547	$	8,776	$	10,737	$	11,431	$	40,491
Service and other revenue		2,790		4,760		4,207		4,302		16,059
Collaboration and license revenue		—		—		—		184		184
Total revenue		12,337		13,536		14,944		15,917		56,734
Costs of goods sold:
Cost of product revenue		4,248		4,455		5,513		6,684		20,900
Cost of services and other revenue		2,082		2,150		2,398		2,368		8,998
Total costs of goods sold and services		6,330		6,605		7,911		9,052		29,898
Gross profit		6,007		6,931		7,033		6,865		26,836
Operating expenses:
Research and development		3,852		4,016		3,924		4,398		16,190
Selling, general and administrative		11,512		13,429		13,352		13,953		52,246
Total operating expenses		15,364		17,445		17,276		18,351		68,436
Loss from operations		(9,357)		(10,514)		(10,243)		(11,486)		(41,600)
Interest income (expense), net		21		42		282		282		627
Other income (expense), net		(47)		(68)		(34)		139		(10)
Income tax benefit (provision)		(22)		(23)		125		107		187
Net loss	$	(9,405)	$	(10,563)	$	(9,870)	$	(10,958)	$	(40,796)
Net loss per share, basic and diluted	$	(0.42)	$	(0.46)	$	(0.37)	$	(0.39)	$	(1.63)
Weighted-average common shares outstanding, basic and diluted		22,422,960		23,213,653		26,627,831		28,021,957		25,090,708


2018	Q1		Q2		Q3		Q4		Total Year
Product revenue	$	4,745	$	5,200	$	5,962	$	7,458	$	23,365
Service and other revenue		2,507		3,174		3,017		3,419		12,117
Collaboration and license revenue		269		269		1,612		—		2,150
Total revenue		7,521		8,643		10,591		10,877		37,632
Costs of goods sold:
Cost of product revenue		2,773		2,945		3,277		3,734		12,729
Cost of services and other revenue		1,576		1,725		1,719		1,935		6,955
Total costs of goods sold and services		4,349		4,670		4,996		5,669		19,684
Gross profit		3,172		3,973		5,595		5,208		17,948
Operating expenses:
Research and development		3,644		3,705		4,411		4,045		15,805
Selling, general and administrative		6,691		7,579		8,846		10,577		33,693
Total operating expenses		10,335		11,284		13,257		14,622		49,498
Loss from operations		(7,163)		(7,311)		(7,662)		(9,414)		(31,550)
Interest income (expense), net		(24)		16		30		24		46
Other income (expense), net		(15)		(48)		(25)		81		(7)
Income tax benefit (provision)		—		—		—		(25)		(25)
Net loss	$	(7,202)	$	(7,343)	$	(7,657)	$	(9,334)	$	(31,536)
Net loss per share, basic and diluted	$	(0.33)	$	(0.34)	$	(0.35)	$	(0.42)	$	(1.43)
Weighted-average common shares outstanding, basic and diluted		21,788,605		21,890,978		22,670,786		22,221,305		21,994,317

Organization and operations (Details) $ / shares in Units, $ in Thousands				1 Months Ended	3 Months Ended								12 Months Ended
	Aug. 08, 2019 USD ($) $ / shares shares	Jun. 05, 2019 USD ($) $ / shares shares	Dec. 04, 2017	Dec. 31, 2017 USD ($) $ / shares shares	Dec. 31, 2019 USD ($) $ / shares shares	Sep. 30, 2019 USD ($)	Jun. 30, 2019 USD ($)	Mar. 31, 2019 USD ($)	Dec. 31, 2018 USD ($) $ / shares shares	Sep. 30, 2018 USD ($)	Jun. 30, 2018 USD ($)	Mar. 31, 2018 USD ($)	Dec. 31, 2019 USD ($) $ / shares shares	Dec. 31, 2018 USD ($) $ / shares shares	Dec. 31, 2017 USD ($) $ / shares shares	Aug. 01, 2019	Jul. 01, 2019	Mar. 19, 2019 USD ($) $ / shares	Jan. 01, 2019 USD ($)
Initial Public Offering
Shares issued \| shares	2,700,000
Common stock, authorized shares \| shares					120,000,000				120,000,000				120,000,000	120,000,000
Preferred stock authorized (in shares) \| shares					47,015,449								47,015,449
Share value \| $ / shares					$ 0.001				$ 0.001				$ 0.001	$ 0.001
Common stock, aggregate offering price					$ 28				$ 22				$ 28	$ 22
stock issuance cost															$ 8,173
Net proceeds from issuance of common shares														(20)	8,423
Accumulated deficit					(216,244)				(175,888)				(216,244)	(175,888)					$ (175,448)
Net loss					(10,958)	$ (9,870)	$ (10,563)	$ (9,405)	(9,334)	$ (7,657)	$ (7,343)	$ (7,202)	(40,796)	(31,536)	(27,019)
Unrestricted cash and cash equivalents				$ 79,682	$ 109,155				$ 44,429				109,155	$ 44,429	$ 79,682
Common stock
Initial Public Offering
Conversion of preferred stock to common stock (in shares) \| shares															14,185,744
Reverse stock split ratio			0.311
Initial Public Offering
Initial Public Offering
Shares issued \| shares				4,916,480
Shares issued price (in dollars per share) \| $ / shares				$ 15.00											$ 15.00
Aggregate net proceeds from IPO				$ 65,600
Conversion of preferred stock to common stock (in shares) \| shares				14,185,744
Carrying value of preferred stock, notes and warrants reclassified as common stock and additional paid-in capital				$ 143,300											$ 143,300
Common stock, authorized shares \| shares				120,000,000											120,000,000
Preferred stock authorized (in shares) \| shares				5,000,000											5,000,000
Initial Public Offering \| Common stock
Initial Public Offering
Shares issued \| shares															4,916,480
Underwritten public offering
Initial Public Offering
Shares issued \| shares	2,700,000
Share value \| $ / shares	$ 0.001
Gross Proceeds From Issuance Of Common Stock	$ 69,000
stock issuance cost	4,500
Net proceeds from issuance of common shares	$ 64,500												$ 64,529
Underwritten public offering \| Common stock
Initial Public Offering
Shares issued \| shares													2,732,673
At-the-market offering
Initial Public Offering
Shares issued \| shares		2,200,000
Shares issued price (in dollars per share) \| $ / shares		$ 22.73
Share value \| $ / shares																		$ 0.001
Gross Proceeds From Issuance Of Common Stock		$ 49,700
stock issuance cost		1,700
Net proceeds from issuance of common shares		$ 48,000											$ 48,019
At-the-market offering \| Maximum
Initial Public Offering
Common stock, aggregate offering price																		$ 50,000
At-the-market offering \| Common stock
Initial Public Offering
Shares issued \| shares													2,186,163
UmanDiagnostics AB Acquisition
Initial Public Offering
Capital stock shares outstanding, percent																95.00%	5.00%
Net loss													$ 100

Significant accounting policies - Revenue recognition - Customers (Details)	12 Months Ended
	Dec. 31, 2019 customer
Revenue recognition
Minimum number of customers	730
Minimum
Revenue recognition
Period of payment	30 days
Maximum
Revenue recognition
Period of payment	45 days

Significant accounting policies - Revenue recognition - Disaggregated revenue (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Revenue recognition
Revenue	$ 15,917	$ 14,944	$ 13,536	$ 12,337	$ 10,877	$ 10,591	$ 8,643	$ 7,521	$ 56,734	$ 37,632	$ 22,874
Product revenue
Revenue recognition
Revenue	11,431	10,737	8,776	9,547	7,458	5,962	5,200	4,745	40,491	23,365	14,124
Product revenue \| NA
Revenue recognition
Revenue									20,398
Product revenue \| EMEA
Revenue recognition
Revenue									14,917
Product revenue \| Asia Pacific
Revenue recognition
Revenue									5,176
Instruments
Revenue recognition
Revenue									14,886
Instruments \| NA
Revenue recognition
Revenue									6,250
Instruments \| EMEA
Revenue recognition
Revenue									5,243
Instruments \| Asia Pacific
Revenue recognition
Revenue									3,393
Consumable and other products
Revenue recognition
Revenue									25,605
Consumable and other products \| NA
Revenue recognition
Revenue									14,148
Consumable and other products \| EMEA
Revenue recognition
Revenue									9,674
Consumable and other products \| Asia Pacific
Revenue recognition
Revenue									1,783
Service and other revenue
Revenue recognition
Revenue	4,302	$ 4,207	$ 4,760	$ 2,790	$ 3,419	3,017	3,174	2,507	16,059	12,117	7,676
Service and other revenue \| NA
Revenue recognition
Revenue									12,809
Service and other revenue \| EMEA
Revenue recognition
Revenue									2,592
Service and other revenue \| Asia Pacific
Revenue recognition
Revenue									658
Service-type warranties
Revenue recognition
Revenue									4,633
Service-type warranties \| NA
Revenue recognition
Revenue									3,139
Service-type warranties \| EMEA
Revenue recognition
Revenue									1,323
Service-type warranties \| Asia Pacific
Revenue recognition
Revenue									171
Research services
Revenue recognition
Revenue									10,005
Research services \| NA
Revenue recognition
Revenue									8,845
Research services \| EMEA
Revenue recognition
Revenue									704
Research services \| Asia Pacific
Revenue recognition
Revenue									456
Other services
Revenue recognition
Revenue									1,421
Other services \| NA
Revenue recognition
Revenue									825
Other services \| EMEA
Revenue recognition
Revenue									565
Other services \| Asia Pacific
Revenue recognition
Revenue									31
Collaboration and license revenue
Revenue recognition
Revenue	$ 184					$ 1,612	$ 269	$ 269	184	$ 2,150	$ 1,074
Collaboration and license revenue \| NA
Revenue recognition
Revenue									167
Collaboration and license revenue \| EMEA
Revenue recognition
Revenue									$ 17

Significant accounting policies - Revenue recognition - Future performance obligations (Details) $ in Millions	Dec. 31, 2019 USD ($)
Transaction Price Allocated to Future Performance Obligations
Amount of transaction price allocated to performance obligations	$ 5.2
Service-type warranties and research services
Transaction Price Allocated to Future Performance Obligations
Amount of transaction price allocated to performance obligations	3.0
Undelivered licenses of intellectual property
Transaction Price Allocated to Future Performance Obligations
Amount of transaction price allocated to performance obligations	1.7
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-01-01
Transaction Price Allocated to Future Performance Obligations
Amount of transaction price allocated to performance obligations	$ 4.7
Revenue recognition period for remaining performance obligation	12 years

Significant accounting policies - Revenue recognition - Changes in deferred revenue from contracts with customers (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2019 USD ($)
Changes in deferred revenue from contracts with customers
Balance at beginning of period	$ 5,957
606 adoption adjustment	(86)
Deferral of revenue	3,925
Recognition of deferred revenue	(4,633)
Balance at end of period	$ 5,163

Significant accounting policies - Revenue recognition - Costs to obtain a contract (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2019 USD ($)
Change in the balance of costs to obtain a contract
606 adoption adjustment	$ 307
Deferral of costs to obtain a contract	848
Recognition of costs to obtain a contract	(820)
Balance at end of period	$ 335

Significant accounting policies - Revenue recognition - Practical expedients (Details)	12 Months Ended
	Dec. 31, 2019
Revenue recognition
Revenue, Practical Expedient, Financing Component [true false]	true
Revenue, Remaining Performance Obligation, Optional Exemption, Performance Obligation [true false]	true

Significant accounting policies - Net loss per share (Details) - shares	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Outstanding potentially dilutive securities that have been excluded in the calculation of diluted net loss per share
Number of dilutive securities excluded in the calculation of diluted net loss per share	2,926,991	2,914,420	2,513,125
Unvested restricted common stock and restricted stock units
Outstanding potentially dilutive securities that have been excluded in the calculation of diluted net loss per share
Number of dilutive securities excluded in the calculation of diluted net loss per share	409,929	361,468	177,192
Outstanding stock options
Outstanding potentially dilutive securities that have been excluded in the calculation of diluted net loss per share
Number of dilutive securities excluded in the calculation of diluted net loss per share	2,507,062	2,476,911	2,249,843
Common stock
Outstanding potentially dilutive securities that have been excluded in the calculation of diluted net loss per share
Number of dilutive securities excluded in the calculation of diluted net loss per share	10,000	76,041	86,090
Obligation to issue warrants, in shares	93,341	93,341	93,341

Significant accounting policies - Cash and Cash equivalents and Restricted cash and deposits (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Cash and Cash equivalents
Cash	$ 6,406	$ 1,821
Money Market funds invested in U.S. Treasury obligations	102,749	42,608
Cash and cash equivalents	109,155	44,429	$ 79,682
Restricted cash and deposits
Restricted cash and deposits	1,100	1,400
Restricted cash	1,026	1,000
Other current and noncurrent assets
Restricted cash and deposits
Restricted cash and deposits		$ 400
Other noncurrent assets
Restricted cash and deposits
Restricted cash and deposits	$ 100

Significant accounting policies - Property and equipment (Details)	12 Months Ended
	Dec. 31, 2019
Laboratory and manufacturing equipment
Property and equipment
Estimated useful life (in years)	5 years
Computers and software
Property and equipment
Estimated useful life (in years)	3 years
Office furniture and equipment
Property and equipment
Estimated useful life (in years)	7 years

Significant accounting policies - Investments (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Investments
Impairment on investments	$ 0.0	$ 0.0	$ 0.0
Minority interest in preferred stock in privately held company
Investments
Purchase price of investment				$ 0.3
Investment in a convertible notes of a privately held company
Investments
Investment principle amount		$ 0.2

Significant accounting policies - Fair value of financial instruments (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Fair value of financial instruments
Cash equivalents	$ 109,155	$ 42,608
Note receivable	150	150
Total	109,305	42,758
Level 1
Fair value of financial instruments
Cash equivalents	109,155	42,608
Total	109,155	42,608
Level 3
Fair value of financial instruments
Note receivable	150	150
Total	$ 150	$ 150

Significant accounting policies - Warranties (Details)	12 Months Ended
Significant accounting policies - Warranties (Details)	Dec. 31, 2019
Significant accounting policies
Warranty period (in years)	1 year

Significant accounting policies - Credit, product and supplier concentrations and off-balance-sheet risk (Details)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Accounts Receivable Concentration
Concentration Risk
Concentration risk (in percent)	50.00%	40.00%
Revenue Concentration
Concentration Risk
Percentage of aggregate accounts receivable accounted by one customer			10.00%
Customer Concentration Risk \| One customer
Concentration Risk
Concentration risk (in percent)	10.00%	10.00%

Significant accounting policies - Stock-based compensation (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Jan. 01, 2019
New Accounting Pronouncement, Early Adoption
Expected dividend yield	0.00%	0.00%	0.00%
Expected term (in years)	6 years	5 years 10 months 24 days	6 years
Weighted-average fair value of options granted	$ 9.09	$ 7.19	$ 4.52
Accumulated deficit	$ (216,244)	$ (175,888)		$ (175,448)
Minimum
New Accounting Pronouncement, Early Adoption
Risk-free interest rate	1.40%	2.60%	1.80%
Expected volatility	33.50%	32.40%	46.00%
Maximum
New Accounting Pronouncement, Early Adoption
Risk-free interest rate	2.60%	3.00%	2.10%
Expected volatility	39.70%	36.80%	52.00%

Significant accounting policies - Recent accounting pronouncements (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Jan. 01, 2019	Dec. 31, 2016
Assets:
Accounts receivable	$ 10,906				$ 6,792				$ 10,906	$ 6,792		$ 6,839
Prepaid expenses and other current assets	2,137				2,330				2,137	2,330		2,618
Other non-current assets	557				536				557	536		555
Liabilities:
Deferred revenue	4,697				5,437				4,697	5,437		5,394
Deferred revenue, net of current portion	466				520				466	520		477
Stockholders’ equity:
Accumulated deficit	(216,244)				(175,888)				(216,244)	(175,888)		(175,448)
Revenue	15,917	$ 14,944	$ 13,536	$ 12,337	10,877	$ 10,591	$ 8,643	$ 7,521	56,734	37,632	$ 22,874
Total costs of goods sold and services	9,052	7,911	6,605	6,330	5,669	4,996	4,670	4,349	29,898	19,684	12,887
Gross profit	6,865	7,033	6,931	6,007	5,208	5,595	3,973	3,172	26,836	17,948	9,987
Selling, general and administrative	13,953	13,352	13,429	11,512	10,577	8,846	7,579	6,691	52,246	33,693	19,688
Net income	(10,958)	(9,870)	(10,563)	(9,405)	(9,334)	(7,657)	(7,343)	(7,202)	(40,796)	(31,536)	(27,019)
Restricted cash	1,026				1,000				1,026	1,000
Minority interest in preferred stock in privately held company
Stockholders’ equity:
Purchase price of investment													$ 300
Investment in a convertible notes of a privately held company
Stockholders’ equity:
Investment principle amount					200					200
Product revenue
Stockholders’ equity:
Revenue	11,431	10,737	8,776	9,547	7,458	5,962	5,200	4,745	40,491	23,365	14,124
Total costs of goods sold and services	6,684	5,513	4,455	4,248	3,734	3,277	2,945	2,773	20,900	12,729	7,742
Service and other revenue
Stockholders’ equity:
Revenue	4,302	4,207	4,760	2,790	3,419	3,017	3,174	2,507	16,059	12,117	7,676
Total costs of goods sold and services	2,368	$ 2,398	$ 2,150	$ 2,082	1,935	$ 1,719	$ 1,725	$ 1,576	8,998	6,955	$ 5,145
Adjustments
Assets:
Accounts receivable					47					47
Prepaid expenses and other current assets	335				288				335	288
Other non-current assets					19					19
Liabilities:
Deferred revenue	(209)				43				(209)	43
Deferred revenue, net of current portion	14				43				14	43
Stockholders’ equity:
Accumulated deficit	(140)				$ (440)				(140)	$ (440)		$ 400
Total costs of goods sold and services									1
Gross profit									327
Selling, general and administrative									27
Net income									300
Adjustments \| Product revenue
Stockholders’ equity:
Revenue									55
Adjustments \| Service and other revenue
Stockholders’ equity:
Revenue									273
Balances without adoption of ASU 606
Assets:
Accounts receivable	10,906								10,906
Prepaid expenses and other current assets	1,802								1,802
Other non-current assets	557								557
Liabilities:
Deferred revenue	4,488								4,488
Deferred revenue, net of current portion	480								480
Stockholders’ equity:
Accumulated deficit	$ (216,104)								(216,104)
Total costs of goods sold and services									29,899
Gross profit									27,163
Selling, general and administrative									52,273
Net income									(40,496)
Balances without adoption of ASU 606 \| Product revenue
Stockholders’ equity:
Revenue									40,546
Balances without adoption of ASU 606 \| Service and other revenue
Stockholders’ equity:
Revenue									$ 16,332

Inventory (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Inventory
Raw Materials	$ 4,717	$ 1,546
Work in process	2,573	2,331
Finished goods	3,173	2,068
Total	$ 10,463	$ 5,945

Property and equipment (Details) - USD ($) $ in Thousands	12 Months Ended
Property and equipment (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Property and equipment
Property and equipment, gross	$ 16,386	$ 5,946
Less: accumulated depreciation	(4,339)	(3,023)
Total	12,047	2,923
Depreciation expense	1,600	700
Laboratory and manufacturing equipment
Property and equipment
Property and equipment, gross	5,391	4,127
Laboratory and manufacturing instruments used internally
Property and equipment
Property and equipment, gross	2,800
Less: accumulated depreciation	(1,200)
Office furniture and equipment
Property and equipment
Property and equipment, gross	1,403	789
Computers and software
Property and equipment
Property and equipment, gross	1,103	786
Leasehold improvements
Property and equipment
Property and equipment, gross	$ 8,489	$ 244

Other accrued expenses - Other accrued expenses (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Other accrued expenses
Accrued inventory	$ 459	$ 599
Accrued royalties	476	323
Accrued professional services	655	723
Accrued development costs	151	795
Accrued other	757	689
Total accrued expenses	$ 2,498	$ 3,129

Other accrued expenses - Other non-current liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Other non-current liabilities
Leasehold obligation incentive	$ 7,572
Deferred Rent	3,009	$ 265
Deferred tax liabilities	2,825	7
Other	1	6
Total non-current liabilities	$ 13,407	$ 278

Income taxes - Components of income (loss) before income taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Components of income (loss) before income taxes
United States	$ (40,010)	$ (31,436)	$ (27,019)
Foreign	(973)	(75)
Loss before income tax	$ (40,983)	$ (31,511)	$ (27,019)

Income taxes - Provision for (benefit from) income taxes (Details) - USD ($)	3 Months Ended					12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Current:
State						$ (20,000)	$ (18,000)
Foreign						(93,000)
Total current income tax provision						(113,000)	(18,000)
Deferred
Federal						(3,000)	(2,000)
State						(1,000)	(5,000)
Foreign						304,000
Total deferred income tax provision (benefit)						300,000	(7,000)
Total income tax provision (benefit)	$ 107,000	$ 125,000	$ (23,000)	$ (22,000)	$ (25,000)	$ 187,000	$ (25,000)	$ 0

Income taxes - Reconciliation of the federal statutory income tax rate to the effective tax rate (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Reconciliation of the federal statutory income tax rate to the effective tax rate
Federal statutory income tax rate (in percent)	21.00%	21.00%
State taxes, net of federal benefit (in percent)	3.20%	6.00%
Tax credits (in percent)	2.30%	2.70%
Share-based compensation (in percent)	2.30%	1.10%
Permanent items (in percent)	(0.90%)	(1.20%)
Defereed tax rate changes	(1.40%)
Change in valuation allowance (in percent)	(24.60%)	(29.90%)
Other (in percent)	(1.40%)	0.20%
Effective income tax rate (in percent)	0.50%	(0.10%)
Aushon acquisition
Income Taxes
Amortizable goodwill		$ 0.4

Income taxes - Deferred tax assets and liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Deferred tax assets:
Net operating loss carryforwards	$ 43,814	$ 35,623
Tax Credits	5,518	4,678
Depreciation		86
Amortization	928	792
Stock-based compensation	973	541
Deferred rent	727
Lease incentive obligation	1,828
Deferred revenue	1,247	1,614
Other deferred tax assets	1,325	1,378
Total deferred tax assets	56,360	44,712
Valuation allowance	(54,137)	(44,033)
Net Deferred tax assets	2,223	679
Section 481(a) Adjustment - Accrued Bonus		(59)
Depreciation	(1,769)
Amortization of acquired intangibles	(3,031)	(610)
Inventory	(212)
Goodwill	(31)	(17)
Other deferred tax liabilities	(5)
Net deferred tax assets (liability)	$ 2,825	$ 7

Income taxes - Other (Details) - USD ($)	12 Months Ended
Income taxes - Other (Details) - USD ($)	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Taxes
Valuation allowance	$ 54,137,000	$ 44,033,000
Increase (decrease) in Valuation allowance	10,100,000
Net operating loss (NOL) carryforwards	$ 174,800,000
Tax credit carryforwards			$ 4,300,000
Cumulative change in ownership related to percentage points	5.00%
Percentage Points Related To Ownership Change	50.00%
Rolling Period Duration Of Ownership Change	3 years
Tax reserves accrued for uncertain tax positions	$ 0	0	0
Accrued interest or penalties	0	0	0
Federal
Income Taxes
Operating Loss Carryforwards, Subject To Expiry			108,500,000
Operating Loss Carryforwards, Not Subject To Expiry			$ 66,300,000
Federal \| Through Tax Year 2039 [Member]
Income Taxes
Tax credit carryforwards	4,300,000
State
Income Taxes
Tax credit carryforwards	$ 1,600,000
State \| Through Tax Year 2039 [Member]
Income Taxes
Net operating loss (NOL) carryforwards		$ 111,900,000

Redeemable convertible preferred stock (Details) $ / shares in Units, $ in Millions		1 Months Ended			12 Months Ended
	Dec. 04, 2017	Nov. 30, 2017 USD ($) $ / shares shares	Jun. 30, 2017 USD ($) $ / shares shares	Jan. 31, 2017 USD ($) $ / shares shares	Dec. 31, 2019 USD ($) $ / shares shares	Dec. 31, 2017 shares
Redeemable convertible preferred stock prior to IPO
Preferred stock, authorized shares					47,015,449
Preferred stock, par value (in dollars per share) \| $ / shares					$ 0.001
Common stock
Redeemable convertible preferred stock prior to IPO
Preferred stock conversion ratio	0.311
Initial Public Offering
Redeemable convertible preferred stock prior to IPO
Preferred stock, authorized shares						5,000,000
Series A-1 Preferred Stock
Redeemable convertible preferred stock prior to IPO
Preferred stock, authorized shares					3,972,415
Series A-2 Preferred Stock
Redeemable convertible preferred stock prior to IPO
Preferred stock, authorized shares					10,492,027
Series A-3 Preferred Stock
Redeemable convertible preferred stock prior to IPO
Preferred stock, authorized shares					2,000,000
Preferred stock, shares issued				700,000
Purchase price \| $ / shares				$ 0.001
Fair value of preferred warrants \| $				$ 2.1
Series B Preferred Stock
Redeemable convertible preferred stock prior to IPO
Preferred stock, authorized shares					6,186,594
Series C Preferred Stock
Redeemable convertible preferred stock prior to IPO
Preferred stock, authorized shares					9,247,089
Preferred stock, shares issued		31,283
Fair value of preferred warrants \| $		$ 0.1
Warrants to purchase shares in cashless		22,809
Milestone Amount \| $					$ 10.0
Series C Preferred Stock ,purchase price $3.3299 per share
Redeemable convertible preferred stock prior to IPO
Preferred stock, shares issued		8,474
Purchase price \| $ / shares		$ 3.3299
Series C-1 Preferred Stock
Redeemable convertible preferred stock prior to IPO
Preferred stock, authorized shares					544,332
Series D Preferred Stock
Redeemable convertible preferred stock prior to IPO
Preferred stock, authorized shares					12,459,090
Series D-1 Preferred Stock
Redeemable convertible preferred stock prior to IPO
Preferred stock, authorized shares					2,113,902
Preferred stock, shares issued			2,113,902
Purchase price \| $ / shares			$ 4.0210
Cash proceeds \| $			$ 8.4

Common Stock, warrants, stock-based compensation, stock options, restricted stock and restricted stock units- Common stock reserved (Details) - shares	Dec. 31, 2019	Dec. 31, 2018
Warrants, stock-based compensation, stock options, restricted stock and restricted stock units
Shares reserved for future awards under compensation plan	882,715	2,433,999
Common stock reserved	3,809,706	5,348,442
Outstanding warrants
Warrants, stock-based compensation, stock options, restricted stock and restricted stock units
Common stock reserved	10,000	76,041
Common stock options and unvested restricted common stock
Warrants, stock-based compensation, stock options, restricted stock and restricted stock units
Common stock reserved	2,916,991	2,838,402

Common Stock, warrants, stock-based compensation, stock options, restricted stock and restricted stock units - Warrants (Details) - $ / shares			12 Months Ended
	Jul. 02, 2019	Jan. 30, 2018	Dec. 31, 2019
Number outstanding
Issued (in shares)		10,000
Weighted Average Exercise Price
Warrants And Rights, Exercised	66,041
Exercise of common stock warrants (in shares)	45,690
Outstanding warrants
Number outstanding
Outstanding at the beginning of the period (in shares)			76,041
Exercised (in shares)			(66,041)
Outstanding at the end of the period (in shares)			10,000
Weighted Average Exercise Price
Outstanding at the beginning of the period (in dollars per share)			$ 10.10
Exercised (in dollars per share)			10.90
Outstanding at the end of the period (in dollars per share)			$ 4.83
Obligation To Issue Warrants, In Shares			93,341

Common Stock, warrants, stock-based compensation, stock options, restricted stock and restricted stock units - Share-based compensation expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Warrants, stock-based compensation, stock options, restricted stock and restricted stock units
Share-based compensation expense	$ 6,388	$ 4,884	$ 2,168
Cost of product revenue
Warrants, stock-based compensation, stock options, restricted stock and restricted stock units
Share-based compensation expense	86	55	24
Cost of service and other revenue
Warrants, stock-based compensation, stock options, restricted stock and restricted stock units
Share-based compensation expense	238	173	52
Research and development
Warrants, stock-based compensation, stock options, restricted stock and restricted stock units
Share-based compensation expense	718	513	180
General and administrative
Warrants, stock-based compensation, stock options, restricted stock and restricted stock units
Share-based compensation expense	$ 5,346	$ 4,143	$ 1,912

Common Stock, warrants, stock-based compensation, stock options, restricted stock and restricted stock units - Stock-based award plans (Details) - shares		3 Months Ended
	Jan. 01, 2020	Sep. 30, 2017	Mar. 31, 2017	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Jun. 30, 2017	Dec. 31, 2016
Warrants, stock-based compensation, stock options, restricted stock and restricted stock units
Common stock available for future awards (in shares)				3,809,706	5,348,442
2007 Plan
Warrants, stock-based compensation, stock options, restricted stock and restricted stock units
Shares authorized under the plan (in shares)		4,350,035					3,852,213	3,229,935
Additional shares authorized		497,822	622,227
Shares available for grant under the plan (in shares)				0
Annual increase in the shares available for grant under the plan (as a percent of shares of common stock outstanding)				4.00%
2017 Plan
Warrants, stock-based compensation, stock options, restricted stock and restricted stock units
Shares authorized under the plan (in shares)						1,042,314
Additional shares authorized	894,761
Shares available for grant under the plan (in shares)				270,143	4,393
2017 ESPP
Warrants, stock-based compensation, stock options, restricted stock and restricted stock units
Shares authorized under the plan (in shares)					425,533
Shares available for grant under the plan (in shares)				612,572
Annual increase in the shares available for grant under the plan (as a percent of shares of common stock outstanding)					1.00%
Outstanding stock options
Warrants, stock-based compensation, stock options, restricted stock and restricted stock units
Options outstanding (in shares)				2,507,062	2,476,911
Outstanding stock options \| 2007 Plan
Warrants, stock-based compensation, stock options, restricted stock and restricted stock units
Options outstanding (in shares)				1,221,746	2,249,843
Common stock issued and outstanding pursuant to the exercise of options (in shares)					571,838
Common stock available for future awards (in shares)					399,379
Shares authorized under the plan (in shares)						2,490,290
Restricted and unrestricted stock awards \| 2007 Plan
Warrants, stock-based compensation, stock options, restricted stock and restricted stock units
Common stock issued and outstanding pursuant to restricted or unrestricted stock awards (in shares)					1,128,975

Common Stock, warrants, stock-based compensation, stock options, restricted stock and restricted stock units - Stock options (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Aggregate intrinsic value
Weighted-average fair value of options granted	$ 9.09	$ 7.19	$ 4.52
Share-based compensation expense	$ 6,388	$ 4,884	$ 2,168
Outstanding stock options
Warrants, stock-based compensation, stock options, restricted stock and restricted stock units
Options expiration period (in years)	10 years
Number outstanding
Outstanding at the beginning of the period (in shares)	2,476,911
Granted (in shares)	882,959
Exercised (in shares)	(414,672)
Cancelled or forfeited (in shares)	(438,136)
Outstanding at the end of the period (in shares)	2,507,062	2,476,911
Vested and expected to vest at the end of the period (in shares)	2,507,062
Exercisable at the end of the period (in shares)	1,284,900
Weighted-average exercise price
Outstanding at the beginning of the period (in dollars per share)	$ 9.65
Granted (in dollars per share)	24.20
Exercised (in dollars per share)	6.80
Cancelled or forfeited (in dollars per share)	14.37
Outstanding at the end of the period (in dollars per share)	14.41	$ 9.65
Vested and expected to vest at the end of the period (in dollars per share)	14.41
Exercisable at the end of the period (in dollars per share)	$ 8.70
Remaining contractual life
Outstanding (in years)	7 years 6 months 29 days	7 years 8 months 23 days
Vested and expected to vest at the end of the period (in years)	7 years 6 months 29 days
Exercisable at the end of the period (in years)	6 years 5 months 16 days
Aggregate intrinsic value
Outstanding at the beginning of the period	$ 22,108
Exercised	6,900	$ 5,300	1,100
Outstanding at the end of the period	24,870	$ 22,108
Vested and expected to vest at the end of the period	24,870
Exercisable at the end of the period	$ 19,239
Weighted-average fair value of options granted	$ 9.09	$ 7.19
Share-based compensation expense	$ 3,700	$ 2,700	1,500
Intrinsic value of stock options exercised	6,900	$ 5,300	$ 1,100
Total unrecognized compensation cost related to unvested stock options	$ 8,700
Period of recognition of unrecognized compensation cost	2 years 9 months 7 days
Outstanding stock options \| Subject to a four year vesting schedule with 25% vesting on the first anniversary and the remaining vesting ratably on a monthly basis over the remaining three years
Warrants, stock-based compensation, stock options, restricted stock and restricted stock units
Vesting period (in years)	4 years
Vesting percentage 1 (as a percent)	25.00%
Outstanding stock options \| Subject to vesting with 50% vesting on December 31, 2018 and December 31, 2019
Warrants, stock-based compensation, stock options, restricted stock and restricted stock units
Vesting period (in years)	3 years
Vesting percentage 1 (as a percent)	75.00%

Common Stock, warrants, stock-based compensation, stock options, restricted stock and restricted stock units - Restricted stock (Details) - Restricted stock - shares	1 Months Ended		12 Months Ended
	Jan. 31, 2015	Dec. 31, 2014	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)			0	0	0
2007 Plan \| Director
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)		78,912
Vesting period (in years)		4 years
2007 Plan \| Executive
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)	781,060
Vesting period (in years)			4 years
2007 Plan \| Executive \| Subject to a four year vesting schedule with 25% vesting on the first anniversary and the remaining vesting ratably on a monthly basis over the remaining three years
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage 1 (as a percent)	25.00%
2007 Plan \| Executive \| Subject to vesting with 50% vesting on December 31, 2018 and December 31, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period (in years)			3 years
Vesting percentage 1 (as a percent)	75.00%

Common Stock, warrants, stock-based compensation, stock options, restricted stock and restricted stock units - Restricted stock units (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Weighted-average grant date fair value per share
Share-based compensation expense	$ 6,388	$ 4,884	$ 2,168
Restricted stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted common stock issued (in shares)	246,588
Number of restricted stock units
Unvested restricted common stock at the beginning of the period (in shares)	321,662
Granted (in shares)	246,588
Vested (in shares)	(136,062)
Cancelled (in shares)	(62,065)
Unvested restricted common stock at the end of the period (in shares)	370,123	321,662
Weighted-average grant date fair value per share
Unvested restricted common stock at the beginning of the period (in dollars per share)	$ 15.84
Granted (in dollars per share)	24.22
Vested (in dollars per share)	17.11
Cancelled (in dollars per share)	18.82
Unvested restricted common stock at the end of the period (in dollars per share)	$ 20.48	$ 15.84
Share-based compensation expense	$ 2,700
Total unrecognized compensation cost related to unvested stock awards	$ 6,900
Period of recognition of unrecognized compensation cost	2 years 9 months 11 days
Restricted stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted common stock issued (in shares)	0	0	0
Number of restricted stock units
Granted (in shares)	0	0	0
Unvested restricted common stock at the end of the period (in shares)	39,806
Weighted-average grant date fair value per share
Unvested restricted common stock at the end of the period (in dollars per share)	$ 3.12
Share-based compensation expense	$ 0	$ 400	$ 600
Aggregate fair value of restricted stock awards	$ 0	$ 2,400	$ 1,900
2017 Plan \| Restricted stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted common stock issued (in shares)	246,588
Number of restricted stock units
Granted (in shares)	246,588
2017 Plan \| Restricted stock units \| Subject to a four year vesting schedule with 25% vesting on the first anniversary and the remaining vesting ratably on a monthly basis over the remaining three years
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted common stock issued (in shares)	135,058
Vesting period 1	4 years
Vesting period 2	3 years
Vesting percentage 1 (as a percent)	25.00%
Vesting percentage 2 (as a percent)	75.00%
Number of restricted stock units
Granted (in shares)	135,058
2017 Plan \| Restricted stock units \| Subject to a four year vesting schedule with 25% vesting on each anniversary
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted common stock issued (in shares)	40,846
Vesting period 1	4 years
Vesting percentage 1 (as a percent)	25.00%
Number of restricted stock units
Granted (in shares)	40,846
2017 Plan \| Restricted stock units \| Vesting on December 31, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted common stock issued (in shares)	15,890
Number of restricted stock units
Granted (in shares)	15,890
2017 Plan \| Restricted stock units \| Vested in equal amounts annually over four years
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period 2	43 months
2017 Plan \| Restricted stock units \| Vested in equal amounts annually over three years
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted common stock issued (in shares)	4,540
Vesting period 1	3 years
Number of restricted stock units
Granted (in shares)	4,540
2017 Plan \| Restricted stock units \| Vesting equally over four years
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted common stock issued (in shares)	10,194
Percentage of shares (as a percent)	10.42%
Number of restricted stock units
Granted (in shares)	10,194
2017 Plan \| Restricted stock units \| Vested immediately upon grant
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted common stock issued (in shares)	5,328
Number of restricted stock units
Granted (in shares)	5,328
2017 Plan \| Restricted stock units \| Vesting ratably over the remaining 45 months
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted common stock issued (in shares)	1,983
Vesting period 3	45 months
Number of restricted stock units
Granted (in shares)	1,983
2017 Plan \| Restricted stock units \| Vesting ratably over the remaining 43 months
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted common stock issued (in shares)	31,732
Number of restricted stock units
Granted (in shares)	31,732
2017 Plan \| Restricted stock units \| Vest upon the one year
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted common stock issued (in shares)	3,000
Vesting period 1	1 year
Number of restricted stock units
Granted (in shares)	3,000

Commitments and contingencies - License agreements and Lease commitments (Details)	12 Months Ended
	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)	Jul. 01, 2019 USD ($)	Oct. 02, 2018 USD ($) ft²
License agreements
Drawing capacity					$ 1,000,000
Letter of credit will be reduced at 41 months after the commencement date	$ 750,000				750,000
Letter of credit will be reduced at 65 months after the commencement date	250,000				$ 250,000
Minimum future rent payments under the lease agreement
2020	2,081,000
2021	3,322,000
2022	3,396,000
2023	3,480,000
2024 and Forward	25,760,000
Total	38,039,000
Rent expense	3,300,000	$ 1,600,000	$ 1,100,000
Other licenses
License agreements
Royalty expense	800,000	400,000	200,000
Annual minimum royalty to be paid under the license agreement	50,000
Tufts \| License agreements
License agreements
Royalty expense	1,000,000	$ 700,000	$ 500,000
Lease for facilities in Billerica, Massachusetts \| Aushon
Lease commitments
Consideration for the early termination				$ 75,000
Company headquarters
License agreements
Term of operating lease					137 months
Square footage of office and laboratory space \| ft²					92,000
Other non-current liabilities [Member]
Lease commitments
Deferred rent expense	$ 3,000,000

Commitments and contingencies - Development and supply agreement and Legal contingencies (Details) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2019 USD ($) $ / shares shares
Commitments and contingencies
Amount payable to counterparty	$ 11.7
Period to purchase minimum number of commercial units	7 years
Fee payable on shortfall of commercial units purchase	$ 9.6
Issuance of supply warrants on termination of agreement, number (in shares) \| shares	93,341
Issuance of supply warrants on termination of agreement, value per share (in dollars per share) \| $ / shares	$ 0.003214

Long term debt (Details)			1 Months Ended	12 Months Ended
Long term debt (Details)	Apr. 15, 2019 installment	Apr. 14, 2014	Aug. 31, 2018 USD ($)	Dec. 31, 2019 USD ($)	Oct. 31, 2018 USD ($)	Oct. 02, 2018 USD ($)
Debt Instrument [Line Items]
Amount borrowed under the loan facility				$ 7,688,000
Drawing capacity						$ 1,000,000
End Of Term Fee				50,000
Loan principal payment installment \| installment	5
Loan agreement
Debt Instrument [Line Items]
Additional amounts available to borrow				$ 0
Amendment 5 to loan agreement
Debt Instrument [Line Items]
Term fee			$ 80,000
Cost incurred upon execution			$ 50,000
Amendment 6 to loan agreement
Debt Instrument [Line Items]
Certificate of deposit associated with the lease					$ 1,000,000
Prime rate \| Loan agreement
Debt Instrument [Line Items]
Margin on variable interest rate (as a percent)		5.25%
Minimum \| Loan agreement
Debt Instrument [Line Items]
Interest rate (as a percent)		8.00%

Long term debt - Debt payment obligations (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Debt payment obligations due based on principal payments
2021	$ 7,688
Debt payment obligations	7,688
Non-cash interest expense	$ 100	$ 200	$ 200

At-the-market offering (Details) - USD ($) $ / shares in Units, $ in Thousands, shares in Millions			12 Months Ended
	Aug. 08, 2019	Jun. 05, 2019	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Mar. 19, 2019
Common stock, aggregate offering price			$ 28	$ 22
Shares issued	2.7
stock issuance cost					$ 8,173
Net proceeds from issuance of common shares				$ (20)	$ 8,423
At-the-market offering
Shares issued		2.2
Shares issued price (in dollars per share)		$ 22.73
Gross proceeds		$ 49,700
stock issuance cost		1,700
Net proceeds from issuance of common shares		$ 48,000	$ 48,019
At-the-market offering \| Maximum
Common stock, aggregate offering price						$ 50,000

Underwritten public Offering (Details) - USD ($) $ / shares in Units, $ in Thousands, shares in Millions		12 Months Ended
	Aug. 08, 2019	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Subsidiary or Equity Method Investee [Line Items]
Shares issued	2.7
Share value		$ 0.001	$ 0.001
stock issuance cost				$ 8,173
Net proceeds from issuance of common shares			$ (20)	$ 8,423
Underwritten public offering
Subsidiary or Equity Method Investee [Line Items]
Shares issued	2.7
Share value	$ 0.001
Gross proceeds	$ 69,000
stock issuance cost	4,500
Net proceeds from issuance of common shares	$ 64,500	$ 64,529

Collaboration and license arrangements (Details) $ in Thousands		1 Months Ended				3 Months Ended									12 Months Ended
	Dec. 22, 2016 USD ($)	Dec. 31, 2018 USD ($)	Jan. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)	Nov. 30, 2012 USD ($)	Dec. 31, 2019 USD ($)	Sep. 30, 2019 USD ($)	Jun. 30, 2019 USD ($)	Mar. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Sep. 30, 2018 USD ($)	Jun. 30, 2018 USD ($)	Mar. 31, 2018 USD ($)	Mar. 31, 2017 USD ($)	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)	Dec. 31, 2015 USD ($)	Dec. 31, 2013 USD ($)
Collaboration and license arrangements
Revenue related to the License and prototype unit																			$ 8,300
Revenue						$ 15,917	$ 14,944	$ 13,536	$ 12,337	$ 10,877	$ 10,591	$ 8,643	$ 7,521		$ 56,734	$ 37,632	$ 22,874
Deferred revenue						1,700									1,700
Increase to deferred revenue															(708)	(1,849)	2,895
Joint development and license agreement
Collaboration and license arrangements
Consideration on collaboration activities					$ 10,000
Number of additional payments					2
Amount of additional payment					$ 5,000
Revenue															200	$ 2,100	200	$ 200
Deferred revenue	$ 1,200
Evaluation and option agreements and license agreement
Collaboration and license arrangements
Revenue				$ 1,800
Number of agreements																		3
Number of fields for which the agreements were entered																		3
Non-refundable license fee				1,000													$ 1,000	$ 2,000
Amount allocated to the option of the related field				$ 800
Amount allocated to the option of the specific field															1,200
Exclusive agreement
Collaboration and license arrangements
Consideration on collaboration activities		$ 500
Deferred revenue						500									500
2016 Amendment
Collaboration and license arrangements
Total allocable consideration	$ 3,200
Increase to deferred revenue														$ 2,000
Royalties						$ 0									$ 0
2016 Amendment \| Maximum
Collaboration and license arrangements
Feasibility Period	3 years
2016 Amendment \| bioMerieux
Collaboration and license arrangements
Cash received			$ 2,000

Employee benefit-plans (Details) - USD ($) $ in Millions	12 Months Ended
Employee benefit-plans (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Employee benefit plans
Contribution made to the 401 (k) Plan	$ 0.5	$ 0.1

Business combinations (Details) - USD ($) $ in Thousands			3 Months Ended								12 Months Ended
Business combinations (Details) - USD ($) $ in Thousands	Aug. 01, 2019	Jan. 30, 2018	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Jul. 01, 2019
Fair value of consideration transferred:
Purchase price, net											$ 14,529	$ 3,801
Assets (liabilities) acquired:
Goodwill			$ 9,353				$ 1,308				9,353	1,308
Revenue			15,917	$ 14,944	$ 13,536	$ 12,337	10,877	$ 10,591	$ 8,643	$ 7,521	56,734	37,632	$ 22,874
Net income			$ (10,958)	$ (9,870)	$ (10,563)	$ (9,405)	$ (9,334)	$ (7,657)	$ (7,343)	$ (7,202)	(40,796)	(31,536)	$ (27,019)
Revenue (unaudited)											57,597	38,753
Pre-tax loss (unaudited)											(38,636)	(33,894)
Aushon acquisition
Fair value of consideration transferred:
Cash		$ 3,200
Obligation to issue cash		800
Cash and cash equivalents acquired		199
Purchase price, net		4,000
Assets (liabilities) acquired:
Accounts receivable		210
Inventory		828
Prepaids and other current assets		71
Property and equipment and other non-current assets		180
Intangibles		2,950
Goodwill		1,308
Total assets acquired		5,746
Contractual obligations		(1,155)
Accounts payable and accrued liabilities		(591)
Total		$ 4,000
Risk-adjusted discount rate used to determine fair value of intangible assets		14.40%
Transaction costs												$ 100
UmanDiagnostics AB Acquisition
Fair value of consideration transferred:
Cash	$ 15,700
Common stock shares consideration	191,152
Common stock	$ 5,500
Capital stock shares outstanding, percent	95.00%													5.00%
Cash and stock paid	$ 21,217
Cash and cash equivalents acquired	1,221
Purchase price, net	19,996
Assets (liabilities) acquired:
Accounts receivable	638
Inventory	1,680
Prepaids and other current assets	114
Property and equipment	33
Intangibles	13,450
Goodwill	8,111
Accounts payable	(20)
Accrued expense and other current liabilities	(871)
Deferred tax liabilities	(3,139)
Total	$ 19,996
Revenue											1,100
Net income											100
Transaction costs											$ 1,900

Goodwill and Acquired Intangible Assets (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Rollforward of goodwill balance
Balance as of beginning of period	$ 1,308
Goodwill acquired	8,111
Cumulative translation adjustment	(66)
Balance as of end of period	9,353	$ 1,308
Purchased intangible assets
Gross Carrying Value	16,400	2,950
Accumulated Amortization	(1,991)	(602)
Cumulative Translation Adjustment	(102)
Net Carrying Value	14,307	2,348
Amortization expense	1,400	$ 600	$ 0
Estimated amortization expense
2020	2,110
2021	2,013
2022	1,930
2023	1,848
2024	1,733
Thereafter	4,673
Estimated Amortization Expenses	14,307
UmanDiagnostics AB Acquisition
Rollforward of goodwill balance
Goodwill acquired	$ 13,500
Purchased intangible assets
Estimated Useful Life	8 years 4 months 24 days
Developed technology
Purchased intangible assets
Estimated Useful Life	7 years	7 years
Gross Carrying Value	$ 1,650	$ 1,650
Accumulated Amortization	(737)	(378)
Net Carrying Value	$ 913	$ 1,272
Weighted average life remaining	5 years 1 month 2 days	6 years 29 days
Customer relationships
Purchased intangible assets
Estimated Useful Life	8 years 6 months	10 years
Gross Carrying Value	$ 1,360	$ 1,250
Accumulated Amortization	(421)	(209)
Cumulative Translation Adjustment	(1)
Net Carrying Value	$ 938	$ 1,041
Weighted average life remaining	8 years 29 days	9 years 29 days
Customer relationships \| UmanDiagnostics AB Acquisition
Rollforward of goodwill balance
Goodwill acquired	$ 100
Trade names
Purchased intangible assets
Estimated Useful Life	3 years	3 years
Gross Carrying Value	$ 50	$ 50
Accumulated Amortization	(32)	(15)
Net Carrying Value	$ 18	$ 35
Weighted average life remaining	1 year 1 month 2 days	2 years 29 days
Know How
Purchased intangible assets
Estimated Useful Life	8 years 6 months
Gross Carrying Value	$ 13,000
Accumulated Amortization	(767)
Cumulative Translation Adjustment	(99)
Net Carrying Value	$ 12,134
Weighted average life remaining	8 years
Know How \| UmanDiagnostics AB Acquisition
Rollforward of goodwill balance
Goodwill acquired	$ 13,000
Noncompete Agreements
Purchased intangible assets
Estimated Useful Life	5 years 6 months
Gross Carrying Value	$ 340
Accumulated Amortization	(34)
Cumulative Translation Adjustment	(2)
Net Carrying Value	$ 304
Weighted average life remaining	5 years
Noncompete Agreements \| UmanDiagnostics AB Acquisition
Rollforward of goodwill balance
Goodwill acquired	$ 400
Maximum \| Customer relationships
Purchased intangible assets
Estimated Useful Life	10 years
Minimum \| Customer relationships
Purchased intangible assets
Estimated Useful Life	8 years 6 months

Related party transactions (Details) - USD ($)	12 Months Ended
Related party transactions (Details) - USD ($)	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Nov. 14, 2019	Nov. 13, 2019	Nov. 28, 2018
Related party transactions
Commitment to sponsor agreement
bioMerieux \| Joint development and license agreement
Related party transactions
Related party revenue	100,000	2,100,000	$ 1,100,000
Tufts \| License Agreement
Related party transactions
Royalty Expense	1,000,000	700,000	500,000
Harvard University
Related party transactions
Related party revenue	100,000
Harvard University \| Maximum
Related party transactions
Related party revenue		100,000	$ 100,000
PPH \| Maximum
Related party transactions
Commitment to sponsor agreement				$ 200,000	$ 120,000	$ 120,000
Total contributions to sponsor agreement	$ 100,000	$ 100,000

Restricted Cash (Details) - USD ($)	Dec. 31, 2019	Dec. 31, 2018	Oct. 02, 2018
Restricted Cash
Restricted cash	$ 1,026,000	$ 1,000,000
Letter of credit will be reduced at 41 months after the commencement date	750,000		$ 750,000
Letter of credit will be reduced at 65 months after the commencement date	$ 250,000		$ 250,000

Quarterly Data (Unaudited) (Details) - USD ($)	3 Months Ended								12 Months Ended
Quarterly Data (Unaudited) (Details) - USD ($)	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Revenue	$ 15,917,000	$ 14,944,000	$ 13,536,000	$ 12,337,000	$ 10,877,000	$ 10,591,000	$ 8,643,000	$ 7,521,000	$ 56,734,000	$ 37,632,000	$ 22,874,000
Cost of goods sold:
Total costs of goods sold and services	9,052,000	7,911,000	6,605,000	6,330,000	5,669,000	4,996,000	4,670,000	4,349,000	29,898,000	19,684,000	12,887,000
Gross profit	6,865,000	7,033,000	6,931,000	6,007,000	5,208,000	5,595,000	3,973,000	3,172,000	26,836,000	17,948,000	9,987,000
Operating expense:
Research and development	4,398,000	3,924,000	4,016,000	3,852,000	4,045,000	4,411,000	3,705,000	3,644,000	16,190,000	15,805,000	16,304,000
Selling, general and administrative	13,953,000	13,352,000	13,429,000	11,512,000	10,577,000	8,846,000	7,579,000	6,691,000	52,246,000	33,693,000	19,688,000
Total operating expenses	18,351,000	17,276,000	17,445,000	15,364,000	14,622,000	13,257,000	11,284,000	10,335,000	68,436,000	49,498,000
Loss from operations	(11,486,000)	(10,243,000)	(10,514,000)	(9,357,000)	(9,414,000)	(7,662,000)	(7,311,000)	(7,163,000)	(41,600,000)	(31,550,000)	(26,005,000)
Interest income (expense), net	282,000	282,000	42,000	21,000	24,000	30,000	16,000	(24,000)	627,000	46,000	(951,000)
Other income (expense), net	139,000	(34,000)	(68,000)	(47,000)	81,000	(25,000)	(48,000)	(15,000)	(10,000)	(7,000)	(63,000)
Income tax benefit (provision)	107,000	125,000	(23,000)	(22,000)	(25,000)				187,000	(25,000)	0
Net loss	$ (10,958,000)	$ (9,870,000)	$ (10,563,000)	$ (9,405,000)	$ (9,334,000)	$ (7,657,000)	$ (7,343,000)	$ (7,202,000)	$ (40,796,000)	$ (31,536,000)	$ (27,019,000)
Net loss per share, basic and diluted	$ (0.39)	$ (0.37)	$ (0.46)	$ (0.42)	$ (0.42)	$ (0.35)	$ (0.34)	$ (0.33)	$ (1.63)	$ (1.43)	$ (8.30)
Weighted-average common shares outstanding, basic and diluted	28,021,957	26,627,831	23,213,653	22,422,960	22,221,305	22,670,786	21,890,978	21,788,605	25,090,708	21,994,317	3,756,954
Product revenue
Revenue	$ 11,431,000	$ 10,737,000	$ 8,776,000	$ 9,547,000	$ 7,458,000	$ 5,962,000	$ 5,200,000	$ 4,745,000	$ 40,491,000	$ 23,365,000	$ 14,124,000
Cost of goods sold:
Total costs of goods sold and services	6,684,000	5,513,000	4,455,000	4,248,000	3,734,000	3,277,000	2,945,000	2,773,000	20,900,000	12,729,000	7,742,000
Service and other revenue
Revenue	4,302,000	4,207,000	4,760,000	2,790,000	3,419,000	3,017,000	3,174,000	2,507,000	16,059,000	12,117,000	7,676,000
Cost of goods sold:
Total costs of goods sold and services	2,368,000	$ 2,398,000	$ 2,150,000	$ 2,082,000	$ 1,935,000	1,719,000	1,725,000	1,576,000	8,998,000	6,955,000	5,145,000
Collaboration and license revenue
Revenue	$ 184,000					$ 1,612,000	$ 269,000	$ 269,000	$ 184,000	$ 2,150,000	$ 1,074,000