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  <xs:element id="osur_DNAGenotekMember" abstract="true" name="DNAGenotekMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="osur_DevelopedTechnologyTradeNamesAndCustomerRelationshipsMember" abstract="true" name="DevelopedTechnologyTradeNamesAndCustomerRelationshipsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="osur_DeferredTaxLiabilitiesRightOfUseAssets" abstract="false" name="DeferredTaxLiabilitiesRightOfUseAssets" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="osur_OtherForeignCountriesMember" abstract="true" name="OtherForeignCountriesMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="osur_TerminationBenefitsLineItems" abstract="true" name="TerminationBenefitsLineItems" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:stringItemType"/>
  <xs:element id="osur_ScheduleOfSupplementalCashFlowInformationRelatedToLeasesTableTableTextBlock" abstract="false" name="ScheduleOfSupplementalCashFlowInformationRelatedToLeasesTableTableTextBlock" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:textBlockItemType"/>
  <xs:element id="osur_FinanceLeaseCost" abstract="false" name="FinanceLeaseCost" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="osur_TerminationBenefitsTextBlock" abstract="false" name="TerminationBenefitsTextBlock" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:textBlockItemType"/>
  <xs:element id="osur_NonCashActivityAbstract" abstract="true" name="NonCashActivityAbstract" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:stringItemType"/>
  <xs:element id="osur_DeferredTaxAssetsDeferredExpenseCapitalizedResearchAndDevelopmentCosts" abstract="false" name="DeferredTaxAssetsDeferredExpenseCapitalizedResearchAndDevelopmentCosts" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="osur_FinanceLeaseAbstract" abstract="true" name="FinanceLeaseAbstract" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:stringItemType"/>
  <xs:element id="osur_FinanceLeaseCost1Abstract" abstract="true" name="FinanceLeaseCost1Abstract" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:stringItemType"/>
  <xs:element id="osur_CashPaidForAmountsIncludedInMeasurementOfLeaseLiabilitiesAbstract" abstract="true" name="CashPaidForAmountsIncludedInMeasurementOfLeaseLiabilitiesAbstract" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:stringItemType"/>
  <xs:element id="osur_TransitionCostsTextBlock" abstract="false" name="TransitionCostsTextBlock" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:textBlockItemType"/>
  <xs:element id="osur_RangeOneMember" abstract="true" name="RangeOneMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="osur_TerminationBenefitsAbstract" abstract="true" name="TerminationBenefitsAbstract" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:stringItemType"/>
  <xs:element id="osur_ShareBasedCompensationArrangementByShareBasedPaymentAwardSharesGrantedOnAchievementPeriod" abstract="false" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardSharesGrantedOnAchievementPeriod" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:durationItemType"/>
  <xs:element id="osur_LesseeOperatingAndFinancingLeasesTextBlock" abstract="false" name="LesseeOperatingAndFinancingLeasesTextBlock" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:textBlockItemType"/>
  <xs:element id="osur_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsExpectedToVestNumber" abstract="false" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsExpectedToVestNumber" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="xbrli:sharesItemType"/>
  <xs:element id="osur_SalesCommissionsAmortizationPeriod" abstract="false" name="SalesCommissionsAmortizationPeriod" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:durationItemType"/>
  <xs:element id="osur_PercentageWithheldUnderGovernmentContractsSubjectToValidationTesting" abstract="false" name="PercentageWithheldUnderGovernmentContractsSubjectToValidationTesting" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="dtr-types1:percentItemType"/>
  <xs:element id="osur_COVID19Member" abstract="true" name="COVID19Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="osur_RangeThreeMember" abstract="true" name="RangeThreeMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="osur_PaymentOfReductionInWorkforce" abstract="false" name="PaymentOfReductionInWorkforce" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="osur_ProductAndServicesMember" abstract="true" name="ProductAndServicesMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="osur_TransitionCostsMember" abstract="true" name="TransitionCostsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="osur_PerformanceBasedRestrictedStockMember" abstract="true" name="PerformanceBasedRestrictedStockMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="osur_TrancheTwoMember" abstract="true" name="TrancheTwoMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="osur_DeferredTaxAssetLeaseLiabilities" abstract="false" name="DeferredTaxAssetLeaseLiabilities" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="osur_CovidNineteenAntibodyMember" abstract="true" name="CovidNineteenAntibodyMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="osur_ContractWithCustomerTimingOfSatisfactionOfPerformanceObligationPaymentPeriod" abstract="false" name="ContractWithCustomerTimingOfSatisfactionOfPerformanceObligationPaymentPeriod" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:durationItemType"/>
  <xs:element id="osur_CommonwealthOfPennsylvaniaMember" abstract="true" name="CommonwealthOfPennsylvaniaMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="osur_LesseeOperatingAndFinanceLeasesPeriodOfOptionsToTerminate" abstract="false" name="LesseeOperatingAndFinanceLeasesPeriodOfOptionsToTerminate" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:durationItemType"/>
  <xs:element id="osur_HcvMember" abstract="true" name="HcvMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="osur_SummaryOfOneTimeTerminationBenefitsTableTextBlock" abstract="false" name="SummaryOfOneTimeTerminationBenefitsTableTextBlock" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:textBlockItemType"/>
  <xs:element id="osur_FundingEarnedNotYetReceived" abstract="false" name="FundingEarnedNotYetReceived" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="osur_ResearchAndDevelopmentExpensesAndOtherIncomeMember" abstract="true" name="ResearchAndDevelopmentExpensesAndOtherIncomeMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="osur_DeferredIncomeTaxExpenseBenefitBeforeValuationAllowance" abstract="false" name="DeferredIncomeTaxExpenseBenefitBeforeValuationAllowance" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="osur_EffectiveIncomeTaxRateReconciliationNondeductibleExecutiveCompensation" abstract="false" name="EffectiveIncomeTaxRateReconciliationNondeductibleExecutiveCompensation" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:percentItemType"/>
  <xs:element id="osur_HivMember" abstract="true" name="HivMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="osur_OtherRevenuesMember" abstract="true" name="OtherRevenuesMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="osur_RegisteredRetirementSavingsPlanMember" abstract="true" name="RegisteredRetirementSavingsPlanMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="osur_TransitionCostsAbstract" abstract="true" name="TransitionCostsAbstract" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:stringItemType"/>
  <xs:element id="osur_SummaryOfGovernmentContractsBalancesIncludedInConsolidatedStatementsOfCashFlowTableTextBlock" abstract="false" name="SummaryOfGovernmentContractsBalancesIncludedInConsolidatedStatementsOfCashFlowTableTextBlock" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:textBlockItemType"/>
  <xs:element id="osur_RiskAssessmentTestingMember" abstract="true" name="RiskAssessmentTestingMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="osur_EmployeeRetentionCredit" abstract="false" name="EmployeeRetentionCredit" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="osur_SapphirosMember" abstract="true" name="SapphirosMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="osur_LesseeOperatingAndFinanceLeaseLiabilityMaturityTableTableTextBlock" abstract="false" name="LesseeOperatingAndFinanceLeaseLiabilityMaturityTableTableTextBlock" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:textBlockItemType"/>
  <xs:element id="osur_EffectiveIncomeTaxRateReconciliationNondeductibleExpenseAndOtherAdjustments" abstract="false" name="EffectiveIncomeTaxRateReconciliationNondeductibleExpenseAndOtherAdjustments" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:percentItemType"/>
  <xs:element id="osur_SeveranceAccrual" abstract="false" name="SeveranceAccrual" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="osur_PurchaseOfPropertyAndEquipmentUnderGovernmentContracts" abstract="false" name="PurchaseOfPropertyAndEquipmentUnderGovernmentContracts" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="osur_CorporateBondsMember" abstract="true" name="CorporateBondsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="osur_TransitionCostsLineItems" abstract="true" name="TransitionCostsLineItems" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:stringItemType"/>
  <xs:element id="osur_AccruedExpensesAndOtherCurrentLiabilities" abstract="false" name="AccruedExpensesAndOtherCurrentLiabilities" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="osur_StockIssuedDuringPeriodSharesVestingOfRestrictedStockAndPerformanceStockUnits" abstract="false" name="StockIssuedDuringPeriodSharesVestingOfRestrictedStockAndPerformanceStockUnits" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:sharesItemType"/>
  <xs:element id="osur_TrancheOneMember" abstract="true" name="TrancheOneMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="osur_EstimatedPenaltiesToBeIncurredUnderMinimumPurchaseCommitments" abstract="false" name="EstimatedPenaltiesToBeIncurredUnderMinimumPurchaseCommitments" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="osur_EstimatedPenaltiesToBeIncurredUnderMinimumPurchaseCommitmentsPenaltyPeriod" abstract="false" name="EstimatedPenaltiesToBeIncurredUnderMinimumPurchaseCommitmentsPenaltyPeriod" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:durationItemType"/>
  <xs:element id="osur_ProceedsFromFundingUnderGovernmentContract" abstract="false" name="ProceedsFromFundingUnderGovernmentContract" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="osur_RangeTwoMember" abstract="true" name="RangeTwoMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="osur_MolecularServicesMember" abstract="true" name="MolecularServicesMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
</xs:schema>
