<?xml version="1.0" encoding="utf-8"?>
<!--XBRL document created with Toppan Merrill Bridge  10.4.0.13 -->
<!--Based on XBRL 2.1-->
<!--Created on: 11/8/2023 12:31:53 AM-->
<!--Modified on: 11/8/2023 12:31:53 AM-->
<xsd:schema xmlns:attributeFormDefault="unqualified" xmlns:xbrli="http://www.xbrl.org/2003/instance" xmlns:xbrldt="http://xbrl.org/2005/xbrldt" xmlns:ref="http://www.xbrl.org/2006/ref" xmlns:link="http://www.xbrl.org/2003/linkbase" xmlns:xl="http://www.xbrl.org/2003/XLink" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" attributeFormDefault="unqualified" elementFormDefault="qualified" targetNamespace="http://www.quanterix.com/20230930" xmlns:us-gaap="http://fasb.org/us-gaap/2023" xmlns:us-types="http://fasb.org/us-types/2023" xmlns:negated="http://www.xbrl.org/2009/role/negated" xmlns:srt-types="http://fasb.org/srt-types/2023" xmlns:dtr-types="http://www.xbrl.org/dtr/type/2022-03-31" xmlns:qtrx="http://www.quanterix.com/20230930" xmlns:enum2="http://xbrl.org/2020/extensible-enumerations-2.0" xmlns:deprecated="http://www.xbrl.org/2009/role/deprecated" xmlns:us-roles="http://fasb.org/us-roles/2023" xmlns:currency="http://xbrl.sec.gov/currency/2023" xmlns:srt-roles="http://fasb.org/srt-roles/2023" xmlns:utr="http://www.xbrl.org/2009/utr" xmlns:sic="http://xbrl.sec.gov/sic/2023" xmlns:stpr="http://xbrl.sec.gov/stpr/2023" xmlns:country="http://xbrl.sec.gov/country/2023" xmlns:net="http://www.xbrl.org/2009/role/net" xmlns:naics="http://xbrl.sec.gov/naics/2023" xmlns:dei="http://xbrl.sec.gov/dei/2023" xmlns:exch="http://xbrl.sec.gov/exch/2023" xmlns:srt="http://fasb.org/srt/2023" xmlns:dtr="http://www.xbrl.org/2009/dtr" xmlns:xbrldi="http://xbrl.org/2006/xbrldi" xmlns:ecd="http://xbrl.sec.gov/ecd/2023" xmlns:ecd-sub="http://xbrl.sec.gov/ecd-sub/2023">
  <xsd:annotation>
    <xsd:appinfo>
      <link:roleType roleURI="http://www.quanterix.com/role/DisclosureStandardAndCustomAxisDomainDefaults" id="DisclosureStandardAndCustomAxisDomainDefaults">
        <link:definition>99900 - Disclosure - Standard And Custom Axis Domain Defaults</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.quanterix.com/role/StatementConsolidatedBalanceSheets" id="StatementConsolidatedBalanceSheets">
        <link:definition>00100 - Statement - CONSOLIDATED BALANCE SHEETS</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.quanterix.com/role/StatementConsolidatedStatementsOfOperations" id="StatementConsolidatedStatementsOfOperations">
        <link:definition>00200 - Statement - CONSOLIDATED STATEMENTS OF OPERATIONS</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.quanterix.com/role/StatementConsolidatedStatementsOfComprehensiveLoss" id="StatementConsolidatedStatementsOfComprehensiveLoss">
        <link:definition>00300 - Statement - CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.quanterix.com/role/StatementConsolidatedStatementOfCashFlows" id="StatementConsolidatedStatementOfCashFlows">
        <link:definition>00500 - Statement - CONSOLIDATED STATEMENT OF CASH FLOWS</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.quanterix.com/role/DisclosureSignificantAccountingPoliciesPresentationOfRestrictedCashDetails" id="DisclosureSignificantAccountingPoliciesPresentationOfRestrictedCashDetails">
        <link:definition>40201 - Disclosure - Significant Accounting Policies - Presentation of Restricted Cash (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.quanterix.com/role/DisclosureFairValueOfFinancialInstrumentsDetails" id="DisclosureFairValueOfFinancialInstrumentsDetails">
        <link:definition>40601 - Disclosure - Fair value of financial instruments (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.quanterix.com/role/DisclosureInventoryDetails" id="DisclosureInventoryDetails">
        <link:definition>40701 - Disclosure - Inventory (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.quanterix.com/role/DisclosureAccruedExpensesAndOtherCurrentLiabilitiesDetails" id="DisclosureAccruedExpensesAndOtherCurrentLiabilitiesDetails">
        <link:definition>40801 - Disclosure - Accrued Expenses and Other Current Liabilities (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.quanterix.com/role/DisclosureLeasesFutureMinimumCommitmentsDetailsCalc2" id="DisclosureLeasesFutureMinimumCommitmentsDetailsCalc2">
        <link:definition>40803 - Disclosure - Leases - Future minimum commitments (Details) (Calc 2)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.quanterix.com/role/DisclosureNetLossPerShareBasicAndDilutedDetails" id="DisclosureNetLossPerShareBasicAndDilutedDetails">
        <link:definition>41001 - Disclosure - Net Loss Per Share - Basic and diluted (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.quanterix.com/role/DisclosureCommitmentsAndContingenciesFutureMinimumCommitmentsDetailsAltCalc" id="DisclosureCommitmentsAndContingenciesFutureMinimumCommitmentsDetailsAltCalc">
        <link:definition>41203 - Disclosure - Commitments and Contingencies - Future minimum commitments (Details) (alt calc)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.quanterix.com/role/DisclosureCommitmentsAndContingenciesFutureMinimumCommitmentsDetails" id="DisclosureCommitmentsAndContingenciesFutureMinimumCommitmentsDetails">
        <link:definition>41303 - Disclosure - Commitments and Contingencies - Future minimum commitments (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.quanterix.com/role/DocumentDocumentAndEntityInformation" id="DocumentDocumentAndEntityInformation">
        <link:definition>00090 - Document - Document and Entity Information</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.quanterix.com/role/StatementConsolidatedBalanceSheetsParenthetical" id="StatementConsolidatedBalanceSheetsParenthetical">
        <link:definition>00105 - Statement - CONSOLIDATED BALANCE SHEETS (Parenthetical)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.quanterix.com/role/StatementConsolidatedStatementsOfStockholdersEquity" id="StatementConsolidatedStatementsOfStockholdersEquity">
        <link:definition>00400 - Statement - CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.quanterix.com/role/DisclosureOrganizationAndNatureOfBusiness" id="DisclosureOrganizationAndNatureOfBusiness">
        <link:definition>10101 - Disclosure - Organization and Nature of Business</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.quanterix.com/role/DisclosureSignificantAccountingPolicies" id="DisclosureSignificantAccountingPolicies">
        <link:definition>10201 - Disclosure - Significant Accounting Policies</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.quanterix.com/role/DisclosureFairValueOfFinancialInstruments" id="DisclosureFairValueOfFinancialInstruments">
        <link:definition>10601 - Disclosure - Fair value of financial instruments</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.quanterix.com/role/DisclosureInventory" id="DisclosureInventory">
        <link:definition>10701 - Disclosure - Inventory</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.quanterix.com/role/DisclosureStockBasedCompensation" id="DisclosureStockBasedCompensation">
        <link:definition>10901 - Disclosure - Stock-Based Compensation</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.quanterix.com/role/DisclosureNetLossPerShare" id="DisclosureNetLossPerShare">
        <link:definition>11001 - Disclosure - Net Loss Per Share</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.quanterix.com/role/DisclosureSignificantAccountingPoliciesPolicies" id="DisclosureSignificantAccountingPoliciesPolicies">
        <link:definition>20202 - Disclosure - Significant Accounting Policies (Policies)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.quanterix.com/role/DisclosureSignificantAccountingPoliciesTables" id="DisclosureSignificantAccountingPoliciesTables">
        <link:definition>30203 - Disclosure - Significant Accounting Policies (Tables)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.quanterix.com/role/DisclosureRevenueAndRelatedMattersTables" id="DisclosureRevenueAndRelatedMattersTables">
        <link:definition>30303 - Disclosure - Revenue and Related Matters (Tables)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.quanterix.com/role/DisclosureMarketableSecuritiesTables" id="DisclosureMarketableSecuritiesTables">
        <link:definition>30503 - Disclosure - Marketable Securities (Tables)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.quanterix.com/role/DisclosureFairValueOfFinancialInstrumentsTables" id="DisclosureFairValueOfFinancialInstrumentsTables">
        <link:definition>30603 - Disclosure - Fair value of financial instruments (Tables)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.quanterix.com/role/DisclosureInventoryTables" id="DisclosureInventoryTables">
        <link:definition>30703 - Disclosure - Inventory (Tables)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.quanterix.com/role/DisclosureStockBasedCompensationTables" id="DisclosureStockBasedCompensationTables">
        <link:definition>30903 - Disclosure - Stock-Based Compensation (Tables)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.quanterix.com/role/DisclosureNetLossPerShareTables" id="DisclosureNetLossPerShareTables">
        <link:definition>31003 - Disclosure - Net Loss Per Share (Tables)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.quanterix.com/role/DisclosureCommitmentsAndContingenciesTables" id="DisclosureCommitmentsAndContingenciesTables">
        <link:definition>31303 - Disclosure - Commitments and contingencies (Tables)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.quanterix.com/role/DisclosureOrganizationAndNatureOfBusinessDetails" id="DisclosureOrganizationAndNatureOfBusinessDetails">
        <link:definition>40101 - Disclosure - Organization and Nature of Business (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.quanterix.com/role/DisclosureRevenueAndRelatedMattersDisaggregatedRevenueDetails" id="DisclosureRevenueAndRelatedMattersDisaggregatedRevenueDetails">
        <link:definition>40301 - Disclosure - Revenue and Related Matters - Disaggregated revenue (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.quanterix.com/role/DisclosureRevenueAndRelatedMattersServiceRevenueDetails" id="DisclosureRevenueAndRelatedMattersServiceRevenueDetails">
        <link:definition>40302 - Disclosure - Revenue and Related Matters - Service Revenue (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.quanterix.com/role/DisclosureRevenueAndRelatedMattersCollaborationAndLicenseArrangementsDetails" id="DisclosureRevenueAndRelatedMattersCollaborationAndLicenseArrangementsDetails">
        <link:definition>40303 - Disclosure - Revenue and Related Matters - Collaboration and license arrangements (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.quanterix.com/role/DisclosureRevenueAndRelatedMattersGrantRevenueDetails" id="DisclosureRevenueAndRelatedMattersGrantRevenueDetails">
        <link:definition>40304 - Disclosure - Revenue and Related Matters - Grant revenue (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.quanterix.com/role/DisclosureRevenueAndRelatedMattersRemainingPerformanceObligationsDetails" id="DisclosureRevenueAndRelatedMattersRemainingPerformanceObligationsDetails">
        <link:definition>40308 - Disclosure - Revenue and Related Matters - Remaining Performance Obligations (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.quanterix.com/role/DisclosureRevenueAndRelatedMattersRemainingPerformanceObligationsDefaultDetails" id="DisclosureRevenueAndRelatedMattersRemainingPerformanceObligationsDefaultDetails">
        <link:definition>40308 - Disclosure - Revenue and Related Matters - Remaining Performance Obligations Default (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.quanterix.com/role/DisclosureMarketableDebtSecuritiesDetails" id="DisclosureMarketableDebtSecuritiesDetails">
        <link:definition>40501 - Disclosure - Marketable Debt Securities (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.quanterix.com/role/DisclosureFairValueOfFinancialInstrumentsChangesInLevel3FinancialInstrumentsDetails" id="DisclosureFairValueOfFinancialInstrumentsChangesInLevel3FinancialInstrumentsDetails">
        <link:definition>40602 - Disclosure - Fair value of financial instruments - Changes in Level 3 Financial Instruments (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.quanterix.com/role/DisclosureFairValueOfFinancialInstrumentsChangesInCarryingValueDetails" id="DisclosureFairValueOfFinancialInstrumentsChangesInCarryingValueDetails">
        <link:definition>40603 - Disclosure - Fair value of financial instruments - Changes in Carrying Value (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.quanterix.com/role/DisclosureStockBasedCompensationStockOptionsDetails" id="DisclosureStockBasedCompensationStockOptionsDetails">
        <link:definition>40901 - Disclosure - Stock-Based Compensation - Stock options (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.quanterix.com/role/DisclosureStockBasedCompensationRestrictedStockUnitsDetails" id="DisclosureStockBasedCompensationRestrictedStockUnitsDetails">
        <link:definition>40902 - Disclosure - Stock-Based Compensation - Restricted stock units (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.quanterix.com/role/DisclosureStockBasedCompensationStockBasedCompensationPlansDetails" id="DisclosureStockBasedCompensationStockBasedCompensationPlansDetails">
        <link:definition>40903 - Disclosure - Stock-Based Compensation - Stock-based compensation plans (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.quanterix.com/role/DisclosureStockBasedCompensationShareBasedCompensationExpenseDetails" id="DisclosureStockBasedCompensationShareBasedCompensationExpenseDetails">
        <link:definition>40904 - Disclosure - Stock-Based Compensation - Share-based compensation expense (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.quanterix.com/role/DisclosureStockBasedCompensationBlackScholesValuationModelAssumptionsDetails" id="DisclosureStockBasedCompensationBlackScholesValuationModelAssumptionsDetails">
        <link:definition>40905 - Disclosure - Stock-Based Compensation - Black-Scholes valuation model Assumptions (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.quanterix.com/role/DisclosureIncomeTaxesDetails" id="DisclosureIncomeTaxesDetails">
        <link:definition>41101 - Disclosure - Income Taxes (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.quanterix.com/role/DisclosureCommitmentsAndContingenciesPurchaseCommitmentsDetails" id="DisclosureCommitmentsAndContingenciesPurchaseCommitmentsDetails">
        <link:definition>41301 - Disclosure - Commitments and Contingencies - Purchase Commitments (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.quanterix.com/role/DisclosureCommitmentsAndContingenciesLicenseAgreementsAndLeaseCommitmentsDetails" id="DisclosureCommitmentsAndContingenciesLicenseAgreementsAndLeaseCommitmentsDetails">
        <link:definition>41302 - Disclosure - Commitments and Contingencies - License agreements and Lease commitments (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.quanterix.com/role/DisclosureRelatedPartyTransactionsDetails" id="DisclosureRelatedPartyTransactionsDetails">
        <link:definition>41401 - Disclosure - Related Party Transactions (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.quanterix.com/role/DisclosureRestructuringDetails" id="DisclosureRestructuringDetails">
        <link:definition>41501 - Disclosure - Restructuring (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.quanterix.com/role/DisclosureRestructuringRollForwardDetails" id="DisclosureRestructuringRollForwardDetails">
        <link:definition>41502 - Disclosure - Restructuring - Roll forward (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.quanterix.com/role/DisclosureVariableInterestEntitiesDetails" id="DisclosureVariableInterestEntitiesDetails">
        <link:definition>41601 - Disclosure - Variable Interest Entities (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.quanterix.com/role/DisclosureRevenueAndRelatedMatters" id="DisclosureRevenueAndRelatedMatters">
        <link:definition>10301 - Disclosure - Revenue and Related Matters</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.quanterix.com/role/DisclosureAllowanceForCreditLosses" id="DisclosureAllowanceForCreditLosses">
        <link:definition>10401 - Disclosure - Allowance for Credit Losses</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.quanterix.com/role/DisclosureMarketableDebtSecurities" id="DisclosureMarketableDebtSecurities">
        <link:definition>10501 - Disclosure - Marketable Debt Securities</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.quanterix.com/role/DisclosureAccruedExpensesAndOtherCurrentLiabilities" id="DisclosureAccruedExpensesAndOtherCurrentLiabilities">
        <link:definition>10801 - Disclosure - Accrued Expenses and Other Current Liabilities</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.quanterix.com/role/DisclosureIncomeTaxes" id="DisclosureIncomeTaxes">
        <link:definition>11101 - Disclosure - Income Taxes</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.quanterix.com/role/DisclosureGoodwill" id="DisclosureGoodwill">
        <link:definition>11201 - Disclosure - Goodwill</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.quanterix.com/role/DisclosureCommitmentsAndContingencies" id="DisclosureCommitmentsAndContingencies">
        <link:definition>11301 - Disclosure - Commitments and Contingencies</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.quanterix.com/role/DisclosureRelatedPartyTransactions" id="DisclosureRelatedPartyTransactions">
        <link:definition>11401 - Disclosure - Related Party Transactions</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.quanterix.com/role/DisclosureRestructuring" id="DisclosureRestructuring">
        <link:definition>11501 - Disclosure - Restructuring</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.quanterix.com/role/DisclosureVariableInterestEntities" id="DisclosureVariableInterestEntities">
        <link:definition>11601 - Disclosure - Variable Interest Entities</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.quanterix.com/role/DisclosureAllowanceForCreditLossesTables" id="DisclosureAllowanceForCreditLossesTables">
        <link:definition>30403 - Disclosure - Allowance for Credit Losses (Tables)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.quanterix.com/role/DisclosureAccruedExpensesAndOtherCurrentLiabilitiesTables" id="DisclosureAccruedExpensesAndOtherCurrentLiabilitiesTables">
        <link:definition>30803 - Disclosure - Accrued Expenses and Other Current Liabilities (Tables)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.quanterix.com/role/DisclosureRestructuringTables" id="DisclosureRestructuringTables">
        <link:definition>31503 - Disclosure - Restructuring (Tables)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.quanterix.com/role/DisclosureRevenueAndRelatedMattersContractAssetsAndLiabilitiesDetails" id="DisclosureRevenueAndRelatedMattersContractAssetsAndLiabilitiesDetails">
        <link:definition>40305 - Disclosure - Revenue and Related Matters - Contract Assets and Liabilities (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.quanterix.com/role/DisclosureRevenueAndRelatedMattersDeferredRevenueDetails" id="DisclosureRevenueAndRelatedMattersDeferredRevenueDetails">
        <link:definition>40306 - Disclosure - Revenue and Related Matters - Deferred Revenue (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.quanterix.com/role/DisclosureRevenueAndRelatedMattersCostsToObtainContractDetails" id="DisclosureRevenueAndRelatedMattersCostsToObtainContractDetails">
        <link:definition>40309 - Disclosure - Revenue and Related Matters - Costs to obtain a contract (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.quanterix.com/role/DisclosureAllowanceForCreditLossesDetails" id="DisclosureAllowanceForCreditLossesDetails">
        <link:definition>40401 - Disclosure - Allowance for Credit Losses (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.quanterix.com/role/DisclosureGoodwillDetails" id="DisclosureGoodwillDetails">
        <link:definition>41201 - Disclosure - Goodwill (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:linkbaseRef xlink:arcrole="http://www.w3.org/1999/xlink/properties/linkbase" xlink:href="tmb-20230930_pre.xml" xlink:role="http://www.xbrl.org/2003/role/presentationLinkbaseRef" xlink:type="simple" />
      <link:linkbaseRef xlink:arcrole="http://www.w3.org/1999/xlink/properties/linkbase" xlink:href="tmb-20230930_def.xml" xlink:role="http://www.xbrl.org/2003/role/definitionLinkbaseRef" xlink:type="simple" />
      <link:linkbaseRef xlink:arcrole="http://www.w3.org/1999/xlink/properties/linkbase" xlink:href="tmb-20230930_lab.xml" xlink:role="http://www.xbrl.org/2003/role/labelLinkbaseRef" xlink:type="simple" />
      <link:linkbaseRef xlink:type="simple" xlink:href="tmb-20230930_cal.xml" xlink:role="http://www.xbrl.org/2003/role/calculationLinkbaseRef" xlink:arcrole="http://www.w3.org/1999/xlink/properties/linkbase" xlink:title="Calculation Links, all" />
    </xsd:appinfo>
  </xsd:annotation>
  <xsd:import namespace="http://xbrl.sec.gov/ecd/2023" schemaLocation="https://xbrl.sec.gov/ecd/2023/ecd-2023.xsd" />
  <xsd:import namespace="http://xbrl.sec.gov/dei/2023" schemaLocation="https://xbrl.sec.gov/dei/2023/dei-2023.xsd" />
  <xsd:import namespace="http://www.xbrl.org/2009/role/negated" schemaLocation="http://www.xbrl.org/lrr/role/negated-2009-12-16.xsd" />
  <xsd:import namespace="http://www.xbrl.org/dtr/type/2022-03-31" schemaLocation="https://www.xbrl.org/dtr/type/2022-03-31/types.xsd" />
  <xsd:import namespace="http://www.xbrl.org/2003/instance" schemaLocation="http://www.xbrl.org/2003/xbrl-instance-2003-12-31.xsd" />
  <xsd:import namespace="http://xbrl.org/2005/xbrldt" schemaLocation="http://www.xbrl.org/2005/xbrldt-2005.xsd" />
  <xsd:import namespace="http://fasb.org/us-roles/2023" schemaLocation="https://xbrl.fasb.org/us-gaap/2023/elts/us-roles-2023.xsd" />
  <xsd:import namespace="http://fasb.org/us-gaap/2023" schemaLocation="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd" />
  <xsd:import namespace="http://fasb.org/srt/2023" schemaLocation="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd" />
  <xsd:import namespace="http://xbrl.sec.gov/ecd-sub/2023" schemaLocation="https://xbrl.sec.gov/ecd/2023/ecd-sub-2023.xsd" />
  <xsd:element id="qtrx_AccruedOtherCost" name="AccruedOtherCost" nillable="true" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" xbrli:balance="credit" />
  <xsd:element id="qtrx_InstrumentProductsMember" name="InstrumentProductsMember" nillable="true" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" abstract="true" xbrli:periodType="duration" />
  <xsd:element id="qtrx_ConsumableAndOtherProductsMember" name="ConsumableAndOtherProductsMember" nillable="true" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" abstract="true" xbrli:periodType="duration" />
  <xsd:element id="qtrx_OtherServicesMember" name="OtherServicesMember" nillable="true" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" abstract="true" xbrli:periodType="duration" />
  <xsd:element id="qtrx_LicenseAgreementsAbstract" name="LicenseAgreementsAbstract" nillable="true" type="xbrli:stringItemType" substitutionGroup="xbrli:item" abstract="true" xbrli:periodType="duration" />
  <xsd:element id="qtrx_CollaborationAndLicenseArrangementsAbstract" name="CollaborationAndLicenseArrangementsAbstract" nillable="true" type="xbrli:stringItemType" substitutionGroup="xbrli:item" abstract="true" xbrli:periodType="duration" />
  <xsd:element id="qtrx_CollaborationAndLicenseArrangementsConsiderationReceived" name="CollaborationAndLicenseArrangementsConsiderationReceived" nillable="true" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" xbrli:balance="debit" />
  <xsd:element id="qtrx_LicenseAgreementsMember" name="LicenseAgreementsMember" nillable="true" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" abstract="true" xbrli:periodType="duration" />
  <xsd:element id="qtrx_TuftsUniversityMember" name="TuftsUniversityMember" nillable="true" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" abstract="true" xbrli:periodType="duration" />
  <xsd:element id="qtrx_CostOfProductRevenueMember" name="CostOfProductRevenueMember" nillable="true" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" abstract="true" xbrli:periodType="duration" />
  <xsd:element id="qtrx_CostOfServiceAndOtherRevenueMember" name="CostOfServiceAndOtherRevenueMember" nillable="true" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" abstract="true" xbrli:periodType="duration" />
  <xsd:element id="qtrx_EmployeeStockPurchase2017PlanMember" name="EmployeeStockPurchase2017PlanMember" nillable="true" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" abstract="true" xbrli:periodType="duration" />
  <xsd:element id="qtrx_ShareBasedCompensationArrangementByShareBasedPaymentAwardEvergreenProvisionAnnualIncreasePercentage" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardEvergreenProvisionAnnualIncreasePercentage" nillable="true" type="dtr-types:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" />
  <xsd:element id="qtrx_ShareBasedCompensationArrangementByShareBasedPaymentAwardEvergreenProvisionNumberOfSharesIncreased" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardEvergreenProvisionNumberOfSharesIncreased" nillable="true" type="xbrli:sharesItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" />
  <xsd:element id="qtrx_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsWeightedAverageRemainingContractualTermAbstract" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsWeightedAverageRemainingContractualTermAbstract" nillable="true" type="xbrli:stringItemType" substitutionGroup="xbrli:item" abstract="true" xbrli:periodType="duration" />
  <xsd:element id="qtrx_HarvardUniversityMember" name="HarvardUniversityMember" nillable="true" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" abstract="true" xbrli:periodType="duration" />
  <xsd:element id="qtrx_ServiceTypeWarrantiesMember" name="ServiceTypeWarrantiesMember" nillable="true" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" abstract="true" xbrli:periodType="duration" />
  <xsd:element id="qtrx_ResearchServicesMember" name="ResearchServicesMember" nillable="true" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" abstract="true" xbrli:periodType="duration" />
  <xsd:element id="qtrx_UndeliveredLicensesOfIntellectualPropertyMember" name="UndeliveredLicensesOfIntellectualPropertyMember" nillable="true" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" abstract="true" xbrli:periodType="duration" />
  <xsd:element id="qtrx_CapitalizedContractCostDeferralOfCostsToObtainContract" name="CapitalizedContractCostDeferralOfCostsToObtainContract" nillable="true" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" xbrli:balance="debit" abstract="false" />
  <xsd:element id="qtrx_CapitalizedContractCostRecognitionOfCostsToObtainContract" name="CapitalizedContractCostRecognitionOfCostsToObtainContract" nillable="true" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" xbrli:balance="debit" />
  <xsd:element id="qtrx_IncreaseDecreaseInOperatingLeaseLiabilities" name="IncreaseDecreaseInOperatingLeaseLiabilities" nillable="true" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" xbrli:balance="debit" />
  <xsd:element id="qtrx_CollaborationAndLicenseArrangementsInitialLicenseFeeReceivable" name="CollaborationAndLicenseArrangementsInitialLicenseFeeReceivable" nillable="true" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" xbrli:balance="credit" abstract="false" />
  <xsd:element id="qtrx_AbbotLicenseAgreementMember" name="AbbotLicenseAgreementMember" nillable="true" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" abstract="true" xbrli:periodType="duration" />
  <xsd:element id="qtrx_RapidAccelerationOfDiagnosticsRadxProgramWorkplanTwoMember" name="RapidAccelerationOfDiagnosticsRadxProgramWorkplanTwoMember" nillable="true" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" abstract="true" xbrli:periodType="duration" />
  <xsd:element id="qtrx_ContractValue" name="ContractValue" nillable="true" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" xbrli:balance="credit" />
  <xsd:element id="qtrx_NumberOfDaysNoticeToTerminateAgreement" name="NumberOfDaysNoticeToTerminateAgreement" nillable="true" type="xbrli:durationItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" />
  <xsd:element id="qtrx_ProceedsFromGrantForAssetPurchase" name="ProceedsFromGrantForAssetPurchase" nillable="true" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" xbrli:balance="debit" />
  <xsd:element id="qtrx_RestrictedStockUnitsAndStockOptionsMember" name="RestrictedStockUnitsAndStockOptionsMember" nillable="true" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" abstract="true" xbrli:periodType="duration" />
  <xsd:element name="CollaborativeArrangementUpfrontPaymentReceived" id="qtrx_CollaborativeArrangementUpfrontPaymentReceived" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="false" xbrli:balance="debit" />
  <xsd:element name="CollaborativeArrangementPaymentReceivedPerQuarter" id="qtrx_CollaborativeArrangementPaymentReceivedPerQuarter" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="false" xbrli:balance="debit" />
  <xsd:element name="CollaborationAgreementMember" id="qtrx_CollaborationAgreementMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="true" />
  <xsd:element name="MasterCollaborationAgreementMember" id="qtrx_MasterCollaborationAgreementMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="true" />
  <xsd:element name="StatementOfWorksAgreementMember" id="qtrx_StatementOfWorksAgreementMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="true" />
  <xsd:element name="EliLillyMember" id="qtrx_EliLillyMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="true" />
  <xsd:element name="AlzheimerSDiseaseDiagnosticFundMember" id="qtrx_AlzheimerSDiseaseDiagnosticFundMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="true" />
  <xsd:element name="UltradxLimitedCompanyMember" id="qtrx_UltradxLimitedCompanyMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="true" />
  <xsd:element name="NumberOfCustomersWithHighPercentOfTotalRevenue" id="qtrx_NumberOfCustomersWithHighPercentOfTotalRevenue" type="xbrli:integerItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="false" />
  <xsd:element name="GoodwillAbstract" id="qtrx_GoodwillAbstract" type="xbrli:stringItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="true" />
  <xsd:element name="OtherLeaseCosts" id="qtrx_OtherLeaseCosts" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="false" xbrli:balance="debit" />
  <xsd:element name="NumberOfCustomersWithHighPercentOfGrossAccountsReceivable" id="qtrx_NumberOfCustomersWithHighPercentOfGrossAccountsReceivable" type="xbrli:integerItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="instant" abstract="false" />
  <xsd:element name="PropertyAndEquipmentMember" id="qtrx_PropertyAndEquipmentMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="true" />
  <xsd:element name="StratecSupplyAgreementMember" id="qtrx_StratecSupplyAgreementMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="true" />
  <xsd:element name="NumberOfDiscsPurchased" id="qtrx_NumberOfDiscsPurchased" type="xbrli:integerItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="false" />
  <xsd:element name="NumberOfDiscsShipped" id="qtrx_NumberOfDiscsShipped" type="xbrli:integerItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="false" />
  <xsd:element name="ThresholdUsedForCalculatingConcentrationOfRisk" id="qtrx_ThresholdUsedForCalculatingConcentrationOfRisk" type="dtr-types:percentItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="false" />
  <xsd:element name="NationalInstitutesOfHealthMember" id="qtrx_NationalInstitutesOfHealthMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="true" />
  <xsd:element name="AccountsReceivableAllowanceForCreditLossWriteOffRecovery" id="qtrx_AccountsReceivableAllowanceForCreditLossWriteOffRecovery" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="false" xbrli:balance="debit" />
  <xsd:element name="ContractPaymentReceived" id="qtrx_ContractPaymentReceived" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="false" xbrli:balance="credit" />
  <xsd:element name="AccruedExpensesAndOtherLiabilitiesCurrent" id="qtrx_AccruedExpensesAndOtherLiabilitiesCurrent" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="instant" abstract="false" xbrli:balance="credit" />
  <xsd:element name="VariableInterestEntityDisclosureAbstract" id="qtrx_VariableInterestEntityDisclosureAbstract" type="xbrli:stringItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="true" />
  <xsd:element name="CollaborationAndLicenseArrangementsContingentConsiderationSharesReceivedNumber" id="qtrx_CollaborationAndLicenseArrangementsContingentConsiderationSharesReceivedNumber" type="xbrli:sharesItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="false" />
  <xsd:element name="EntityNumberOfProjectedCompleted" id="qtrx_EntityNumberOfProjectedCompleted" type="xbrli:integerItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="instant" abstract="false" />
  <xsd:element name="EntityNumberOfCustomersServed" id="qtrx_EntityNumberOfCustomersServed" type="xbrli:integerItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="instant" abstract="false" />
  <xsd:element name="CollaborationAndLicenseArrangementsContingentShareAmountReceivable" id="qtrx_CollaborationAndLicenseArrangementsContingentShareAmountReceivable" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="instant" abstract="false" xbrli:balance="debit" />
  <xsd:element name="AccruedLiabilitiesAndOtherLiabilitiesDisclosureCurrentTextBlock" id="qtrx_AccruedLiabilitiesAndOtherLiabilitiesDisclosureCurrentTextBlock" type="dtr-types:textBlockItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="false" />
  <xsd:element name="AccruedLiabilitiesAndOtherLiabilitiesCurrentAbstract" id="qtrx_AccruedLiabilitiesAndOtherLiabilitiesCurrentAbstract" type="xbrli:stringItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="true" />
  <xsd:element name="AccruedLiabilitiesAndOtherLiabilitiesCurrentTableTextBlock" id="qtrx_AccruedLiabilitiesAndOtherLiabilitiesCurrentTableTextBlock" type="dtr-types:textBlockItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="false" />
  <xsd:element name="TenantImprovementsAllowancesReimbursement" id="qtrx_TenantImprovementsAllowancesReimbursement" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="false" xbrli:balance="debit" />
  <xsd:element name="ScheduleOfShareBasedPaymentAwardStockOptionsAndEmployeeStockPurchasePlanValuationAssumptionsTableTextBlock" id="qtrx_ScheduleOfShareBasedPaymentAwardStockOptionsAndEmployeeStockPurchasePlanValuationAssumptionsTableTextBlock" type="dtr-types:textBlockItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="false" />
  <xsd:element name="EmployeeStockPurchasePlanAwardsMember" id="qtrx_EmployeeStockPurchasePlanAwardsMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="true" />
  <xsd:element name="UpfrontFee" id="qtrx_UpfrontFee" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="false" xbrli:balance="credit" />
  <xsd:element name="DebtSecuritiesAvailableForSaleMaturityAllocatedAndSingleMaturityDateRollingWithinOneToTwoYearsFairValue" id="qtrx_DebtSecuritiesAvailableForSaleMaturityAllocatedAndSingleMaturityDateRollingWithinOneToTwoYearsFairValue" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="instant" abstract="false" xbrli:balance="debit" />
  <xsd:element name="DebtSecuritiesAvailableForSaleMaturityAllocatedAndSingleMaturityDateRollingBetweenOneToTwoYearsAmortizedCost" id="qtrx_DebtSecuritiesAvailableForSaleMaturityAllocatedAndSingleMaturityDateRollingBetweenOneToTwoYearsAmortizedCost" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="instant" abstract="false" xbrli:balance="debit" />
  <xsd:element name="SharesReceivedAsConsiderationUnderProductSalesAgreement" id="qtrx_SharesReceivedAsConsiderationUnderProductSalesAgreement" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="false" xbrli:balance="credit" />
  <xsd:element name="GrantsReceived" id="qtrx_GrantsReceived" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="instant" abstract="false" xbrli:balance="credit" />
  <xsd:element name="LaurieOlsonMember" id="qtrx_LaurieOlsonMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="true" />
  <xsd:element name="ExerciseOfStockOptionsArrangementMember" id="qtrx_ExerciseOfStockOptionsArrangementMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="true" />
  <xsd:element name="MartinMadausMember" id="qtrx_MartinMadausMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="true" />
  <xsd:element name="SaleOfStockArrangementMember" id="qtrx_SaleOfStockArrangementMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="true" />
  <xsd:element name="FairValueMeasurementWithUnobservableInputsReconciliationNonRecurringBasisAssetGainLossIncludedInEarnings" id="qtrx_FairValueMeasurementWithUnobservableInputsReconciliationNonRecurringBasisAssetGainLossIncludedInEarnings" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="false" xbrli:balance="credit" />
</xsd:schema>
