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  <xs:element id="exdx_FinanceLeaseLiabilityToBePaidDueAfterYearFour" abstract="false" name="FinanceLeaseLiabilityToBePaidDueAfterYearFour" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="exdx_PurchaseObligationAnnualIncreaseInCommitmentPercentage" abstract="false" name="PurchaseObligationAnnualIncreaseInCommitmentPercentage" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="dtr-types:percentItemType"/>
  <xs:element id="exdx_RoyaltyObligationPercentageOfSales" abstract="false" name="RoyaltyObligationPercentageOfSales" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="dtr-types:percentItemType"/>
  <xs:element id="exdx_JanssenPromotionAgreementMember" abstract="true" name="JanssenPromotionAgreementMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="exdx_DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsCapitalizationOfResearchAndExperimentationCosts" abstract="false" name="DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsCapitalizationOfResearchAndExperimentationCosts" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="exdx_ClientMember" abstract="true" name="ClientMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
</xs:schema>
