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<!-- DFIN ActiveDisclosure(SM) XBRL Schema Document - http://www.dfinsolutions.com/ -->
<!-- Creation Date      : 2022-02-24T20:58:48.3739446+00:00 -->
<!-- Version            : 5.0.1.728 -->
<!-- Package ID         : 46d96e1f710f4318b37f0d418ce7999e -->
<!-- Copyright (c) 2022 Donnelley Financial Solutions, Inc. All Rights Reserved. -->
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  <xsd:element id="psnl_RepaymentsOfPaymentAgreementsWithFinancingEntity" name="RepaymentsOfPaymentAgreementsWithFinancingEntity" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit" />
  <xsd:element id="psnl_ReconciliationOfCashCashEquivalentsAndRestrictedCashAbstract" name="ReconciliationOfCashCashEquivalentsAndRestrictedCashAbstract" type="xbrli:stringItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="psnl_RedeemableConvertiblePreferredStockDisclosureTextBlock" name="RedeemableConvertiblePreferredStockDisclosureTextBlock" type="dtr-types:textBlockItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="psnl_RedeemableConvertiblePreferredStockWarrantsTextBlock" name="RedeemableConvertiblePreferredStockWarrantsTextBlock" type="dtr-types:textBlockItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="psnl_ConvertiblePreferredStockWarrantsAbstract" name="ConvertiblePreferredStockWarrantsAbstract" type="xbrli:stringItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="psnl_CommonStockWarrantsDisclosureTextBlock" name="CommonStockWarrantsDisclosureTextBlock" type="dtr-types:textBlockItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="psnl_CommonStockWarrantsAbstract" name="CommonStockWarrantsAbstract" type="xbrli:stringItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="psnl_ReverseStockSplitPolicyPolicyTextBlock" name="ReverseStockSplitPolicyPolicyTextBlock" type="dtr-types:textBlockItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="psnl_InitialPublicOfferingPolicyTextBlock" name="InitialPublicOfferingPolicyTextBlock" type="dtr-types:textBlockItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="psnl_FollowOnAndAtMarketEquityOfferingsPolicyTextBlock" name="FollowOnAndAtMarketEquityOfferingsPolicyTextBlock" type="dtr-types:textBlockItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="psnl_ConcentrationOfCreditRiskAndOtherRisksAndUncertaintiesPolicyPolicyTextBlock" name="ConcentrationOfCreditRiskAndOtherRisksAndUncertaintiesPolicyPolicyTextBlock" type="dtr-types:textBlockItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="psnl_ShortTermInvestmentsPolicyPolicyTextBlock" name="ShortTermInvestmentsPolicyPolicyTextBlock" type="dtr-types:textBlockItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="psnl_InventoryAndOtherDeferredCostsPolicyPolicyTextBlock" name="InventoryAndOtherDeferredCostsPolicyPolicyTextBlock" type="dtr-types:textBlockItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="psnl_JumpstartOurBusinessStartupsActAccountingElectionPolicyPolicyTextBlock" name="JumpstartOurBusinessStartupsActAccountingElectionPolicyPolicyTextBlock" type="dtr-types:textBlockItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="psnl_ScheduleOfInventoryAndOtherDeferredCostsTableTextBlock" name="ScheduleOfInventoryAndOtherDeferredCostsTableTextBlock" type="dtr-types:textBlockItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="psnl_AccruedLiabilitiesAndOtherLiabilitiesDisclosureCurrentTableTextBlock" name="AccruedLiabilitiesAndOtherLiabilitiesDisclosureCurrentTableTextBlock" type="dtr-types:textBlockItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="psnl_ScheduleOfChangesInFairValueOfLevelThreeFinancialInstrumentsTableTextBlock" name="ScheduleOfChangesInFairValueOfLevelThreeFinancialInstrumentsTableTextBlock" type="dtr-types:textBlockItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="psnl_SummaryOfSharesOfCommonStockAvailableForIssuanceTableTextBlock" name="SummaryOfSharesOfCommonStockAvailableForIssuanceTableTextBlock" type="dtr-types:textBlockItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="psnl_PerformanceBasedStockOptionMember" name="PerformanceBasedStockOptionMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="psnl_TwoThousandNineteenEquityIncentivePlanMember" name="TwoThousandNineteenEquityIncentivePlanMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="psnl_TwoThousandNineteenEmployeeStockPurchasePlanMember" name="TwoThousandNineteenEmployeeStockPurchasePlanMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="psnl_SummaryOfSignificantAccountingPoliciesLineItems" name="SummaryOfSignificantAccountingPoliciesLineItems" type="xbrli:stringItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="psnl_SummaryOfSignificantAccountingPoliciesTable" name="SummaryOfSignificantAccountingPoliciesTable" type="xbrli:stringItemType" substitutionGroup="xbrldt:hypercubeItem" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="psnl_FollowOnOfferingMember" name="FollowOnOfferingMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="psnl_FollowOnEquityOfferingsMember" name="FollowOnEquityOfferingsMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="psnl_AtMarketSalesAgreementMember" name="AtMarketSalesAgreementMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="psnl_InitialPublicOfferingIssuanceCosts" name="InitialPublicOfferingIssuanceCosts" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit" />
  <xsd:element id="psnl_ExpensesRelatedToFollowOnOffering" name="ExpensesRelatedToFollowOnOffering" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit" />
  <xsd:element id="psnl_CommissionPercentageOfSaleProceedsFromCommonStock" name="CommissionPercentageOfSaleProceedsFromCommonStock" type="dtr-types:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="psnl_VeteransAffairsMillionVeteranProgramMember" name="VeteransAffairsMillionVeteranProgramMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="psnl_NateraIncMember" name="NateraIncMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="psnl_MerckCoIncMember" name="MerckCoIncMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="psnl_PfizerIncMember" name="PfizerIncMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="psnl_AbbVieIncMember" name="AbbVieIncMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="psnl_ContractWithCustomerStandardPaymentTerms" name="ContractWithCustomerStandardPaymentTerms" type="xbrli:durationItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="psnl_PeriodBetweenPaymentByCustomerAndTransferOfPromisedServices" name="PeriodBetweenPaymentByCustomerAndTransferOfPromisedServices" type="xbrli:durationItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="psnl_RecognitionPeriodOfIncrementalCosts" name="RecognitionPeriodOfIncrementalCosts" type="xbrli:durationItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="psnl_AllOtherCustomersMember" name="AllOtherCustomersMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="psnl_SignificantCustomersMember" name="SignificantCustomersMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="psnl_InventoryAndOtherDeferredCostsAbstract" name="InventoryAndOtherDeferredCostsAbstract" type="xbrli:stringItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="psnl_ComputerSoftwareCostsMember" name="ComputerSoftwareCostsMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="psnl_ContractWithCustomerDepositsCurrent" name="ContractWithCustomerDepositsCurrent" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit" />
  <xsd:element id="psnl_AssetsAmortizedCostBasis" name="AssetsAmortizedCostBasis" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="debit" />
  <xsd:element id="psnl_LongTermMarketableDebtSecuritiesMaturityPeriod" name="LongTermMarketableDebtSecuritiesMaturityPeriod" type="xbrli:durationItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="psnl_LongTermInvestmentsMember" name="LongTermInvestmentsMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="psnl_WarrantLiabilityMember" name="WarrantLiabilityMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="psnl_LineOfCreditFacilityMaturityDate" name="LineOfCreditFacilityMaturityDate" type="xbrli:dateItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="psnl_LineOfCreditFacilityExtendedMaturityDate" name="LineOfCreditFacilityExtendedMaturityDate" type="xbrli:dateItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="psnl_DebtDisclosureLineItems" name="DebtDisclosureLineItems" type="xbrli:stringItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="psnl_DebtDisclosureTable" name="DebtDisclosureTable" type="xbrli:stringItemType" substitutionGroup="xbrldt:hypercubeItem" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="psnl_TriplePointCapitalLimitedLiabilityCompanyMember" name="TriplePointCapitalLimitedLiabilityCompanyMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="psnl_SeriesCRedeemableConvertiblePreferredStockMember" name="SeriesCRedeemableConvertiblePreferredStockMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="psnl_PaymentAgreementWithFinancingEntityMember" name="PaymentAgreementWithFinancingEntityMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="psnl_TrancheOneMember" name="TrancheOneMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="psnl_TrancheTwoMember" name="TrancheTwoMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="psnl_TrancheThreeMember" name="TrancheThreeMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="psnl_EstimatedFairValueOfWarrants" name="EstimatedFairValueOfWarrants" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit" />
  <xsd:element id="psnl_PercentageOfPrepaymentFee" name="PercentageOfPrepaymentFee" type="dtr-types:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="psnl_PercentageOfPrinciplePaymentAmount" name="PercentageOfPrinciplePaymentAmount" type="dtr-types:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="psnl_NumberOfEqualPayments" name="NumberOfEqualPayments" type="xbrli:integerItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="psnl_DebtInstrumentNoninterestBearingRate" name="DebtInstrumentNoninterestBearingRate" type="dtr-types:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" />
  <xsd:element id="psnl_DebtInstrumentImputedInterestRate" name="DebtInstrumentImputedInterestRate" type="dtr-types:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" />
  <xsd:element id="psnl_InitialPresentValueOfDebt" name="InitialPresentValueOfDebt" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit" />
  <xsd:element id="psnl_CoLocatedDataCenterSpaceMember" name="CoLocatedDataCenterSpaceMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="psnl_FutureCorporateHeadquartersAndExpandedLaboratoryFacilityMember" name="FutureCorporateHeadquartersAndExpandedLaboratoryFacilityMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="psnl_ChinaOperationsMember" name="ChinaOperationsMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="psnl_OperatingLeaseLandlordAgreedToContributionAmount" name="OperatingLeaseLandlordAgreedToContributionAmount" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit" />
  <xsd:element id="psnl_SeriesARedeemableConvertiblePreferredStockMember" name="SeriesARedeemableConvertiblePreferredStockMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="psnl_SeriesBRedeemableConvertiblePreferredStockMember" name="SeriesBRedeemableConvertiblePreferredStockMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="psnl_NumberOfFractionalSharesIssued" name="NumberOfFractionalSharesIssued" type="xbrli:sharesItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" />
  <xsd:element id="psnl_NumberOfIssuedCommonSharesReducedUponConversion" name="NumberOfIssuedCommonSharesReducedUponConversion" type="xbrli:sharesItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" />
  <xsd:element id="psnl_TwoThousandElevenEquityIncentivePlanMember" name="TwoThousandElevenEquityIncentivePlanMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="psnl_OptionsGrantedAsMeritAwardsMember" name="OptionsGrantedAsMeritAwardsMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="psnl_ShareBasedCompensationByShareBasedPaymentAwardPercentageOfExercisePriceOfOptionsGranted" name="ShareBasedCompensationByShareBasedPaymentAwardPercentageOfExercisePriceOfOptionsGranted" type="dtr-types:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="psnl_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOptionsAndOtherThanOptionsGrantsInPeriodOutstandingAndNotVested" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOptionsAndOtherThanOptionsGrantsInPeriodOutstandingAndNotVested" type="xbrli:sharesItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" />
  <xsd:element id="psnl_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodOutstandingAndNotVested" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodOutstandingAndNotVested" type="xbrli:sharesItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" />
  <xsd:element id="psnl_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAndEquityInstrumentsOtherThanOptionsGrantsInPeriodUnvestedAndUnexercisedButReservedSharesYetGranted" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAndEquityInstrumentsOtherThanOptionsGrantsInPeriodUnvestedAndUnexercisedButReservedSharesYetGranted" type="xbrli:sharesItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" />
  <xsd:element id="psnl_TwoThousandNineteenPlanMember" name="TwoThousandNineteenPlanMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="psnl_TwoThousandTwentyInducementPlanMember" name="TwoThousandTwentyInducementPlanMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="psnl_TwoThousandElevenAndTwoThousandNineteenEquityIncentivePlanAndTwoThousandTwentyInducementPlanMember" name="TwoThousandElevenAndTwoThousandNineteenEquityIncentivePlanAndTwoThousandTwentyInducementPlanMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="psnl_ClosingPriceOfCommonStock" name="ClosingPriceOfCommonStock" type="dtr-types:perShareItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" />
  <xsd:element id="psnl_ShareBasedCompensationArrangementByShareBasedPaymentEqualToOrGreaterThanAverageMarketCapital" name="ShareBasedCompensationArrangementByShareBasedPaymentEqualToOrGreaterThanAverageMarketCapital" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit" />
  <xsd:element id="psnl_ShareBasedCompensationArrangementByShareBasedPaymentAverageMarketCapitalizationThresholdSatisfactionPeriod" name="ShareBasedCompensationArrangementByShareBasedPaymentAverageMarketCapitalizationThresholdSatisfactionPeriod" type="xbrli:durationItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="psnl_TwoThousandNineteenEquityIncentivePlanAndTwoThousandTwentyInducementPlanMember" name="TwoThousandNineteenEquityIncentivePlanAndTwoThousandTwentyInducementPlanMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="psnl_EmployeeStockPurchasePlanMember" name="EmployeeStockPurchasePlanMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="psnl_ConvertiblePreferredStockWarrantsLineItems" name="ConvertiblePreferredStockWarrantsLineItems" type="xbrli:stringItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="psnl_ConvertiblePreferredStockWarrantsTable" name="ConvertiblePreferredStockWarrantsTable" type="xbrli:stringItemType" substitutionGroup="xbrldt:hypercubeItem" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="psnl_TermLoanMember" name="TermLoanMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="psnl_SiliconValleyBankMember" name="SiliconValleyBankMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="psnl_EstimatedFairValueConvertiblePreferredStockWarrant" name="EstimatedFairValueConvertiblePreferredStockWarrant" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="psnl_ReclassificationOfOutstandingPreferredStockWarrantLiabilityToAdditionalPaidInCapitalFairValue" name="ReclassificationOfOutstandingPreferredStockWarrantLiabilityToAdditionalPaidInCapitalFairValue" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit" />
  <xsd:element id="psnl_WarrantExercised" name="WarrantExercised" type="xbrli:sharesItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="psnl_CommonStockIssuedForExerciseOfWarrant" name="CommonStockIssuedForExerciseOfWarrant" type="xbrli:sharesItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="psnl_CommonStockWarrantsLineItems" name="CommonStockWarrantsLineItems" type="xbrli:stringItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="psnl_CommonStockWarrantsTable" name="CommonStockWarrantsTable" type="xbrli:stringItemType" substitutionGroup="xbrldt:hypercubeItem" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="psnl_OptionsToPurchaseCommonStockMember" name="OptionsToPurchaseCommonStockMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="psnl_UnvestedRestrictedStockUnitsMember" name="UnvestedRestrictedStockUnitsMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="psnl_IncomeTaxDisclosureLineItems" name="IncomeTaxDisclosureLineItems" type="xbrli:stringItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="psnl_IncomeTaxDisclosureTable" name="IncomeTaxDisclosureTable" type="xbrli:stringItemType" substitutionGroup="xbrldt:hypercubeItem" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="psnl_DeferredSocialPayrollTaxesCoronavirusAidReliefAndEconomicSecurityAct" name="DeferredSocialPayrollTaxesCoronavirusAidReliefAndEconomicSecurityAct" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit" />
  <xsd:element id="psnl_PayrollTaxesPaidCoronavirusAidReliefAndEconomicSecurityAct" name="PayrollTaxesPaidCoronavirusAidReliefAndEconomicSecurityAct" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit" />
  <xsd:element id="psnl_DeferredTaxAssetsOperatingLeaseLiabilities" name="DeferredTaxAssetsOperatingLeaseLiabilities" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="debit" />
  <xsd:element id="psnl_DeferredTaxAssetsOtherIntangibleAssets" name="DeferredTaxAssetsOtherIntangibleAssets" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="debit" />
  <xsd:element id="psnl_DeferredTaxLiabilitiesOperatingLeaseRightOfUseAssets" name="DeferredTaxLiabilitiesOperatingLeaseRightOfUseAssets" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit" />
  <xsd:element id="psnl_OperatingLossCarryforwardsExpirationYear" name="OperatingLossCarryforwardsExpirationYear" type="xbrli:gYearItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="psnl_TaxCreditCarryForwardExpirationYear" name="TaxCreditCarryForwardExpirationYear" type="xbrli:gYearItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
</xsd:schema>
