Description:ProductName:FreePSA#ofSamples:1x96AssaysIntendedUse:FreePSAkitisadirectsolidphaseenzymeimmunoassayforquantitativedeterminationoffreeProstaticSpecificAntigen(fPSA)inhumanserum.Introduction:ProstateSpecificantigen(PSA)isaserineproteasewithchymotrypsin-likeactivity.Theproteinisasinglechainglycoproteinwithamolecularweightof28.4kDA.PSAderivesitsnamefromtheobservationthatitisanormalantigenoftheprostratebutisnotfoundinanyothernormalormalignanttissue.PSAisreleasedfromthenormalprostateandappearsatlowserumconcentrationsinhealthymen.Studieswithreversetranscription-PCRhaveshownthatPSAalsoisexpressedatalowconcentrationinperipheralbloodcellsandothertissues.Highserumconcentrationscanbedetectedinpatientswithadvancedprostatecancer(PCA).ThereforePSAisappliedasatumorMarkerfortheclinicalmanagementofPCA.However,increasedPSAconcentrationsinserumalsooccurinpatientswithbenignprostatehyperplasia(BPH).HencethegoalistodiscriminateclearlybetweenBPHandPCAintheclinicallaboratorytosparethepatientinvasivediagnosticprocedures,suchasaprostatebiopsy.InhumanserumPSAoccursintwoforms:freePSA(f-PSA)andcomplexedPSA.ThemajorformisacomplexofPSAandα1-antichymotrypsin(ACT).Thefractionoff-PSAwasshowntobesubstantiallysmallerinpatientswithuntreatedPCAthaninpatientswithBPH.Thereforecombinedmeasurementsoff-PSAandtotalPSA(t-PSA)mayleadtoabetterdiscriminationbetweenBPHandPCA.Somerecentstudieshavealreadyshownthatthef-PSA/t-PSAratioishelpfulinthedifferentialdiagnosisofBPHandPCA.PSAisfoundinbenign,malignantandmetastaticprostratecancer.Sinceprostatecanceristhesecondmostprevalentformofmalemalignancy,thedetectionofelevatedPSAlevelsplaysanimportantroleintheearlydiagnosis.SerumPSAlevelshavebeenfoundtobemoreusefulthanprostaticacidphosphatase(PAP)inthediagnosisandmanagementofpatientsduetoincreasedsensitivity.Principlesoftheassay:Inthismethod,standards,patientspecimensand/orcontrols(containingthenativefPSAantigen)arefirstaddedtostreptavidincoatedwells.Biotinylatedmonoclonalandenzymelabelledantibodiesarethenaddedandthereactantsaremixed:theseantibodieshavehighaffinityandspecificityandaredirectedagainstdistinctanddifferentepitopesoffPSA.StorageandStABIlity:Theclosedreagentsarestableuptotheexpirydatestatedonthelabelwhenstoredat+2…+8°Cinthedark.Openedreagentsarestablefor60dayswhenstoredat+2…+8°C.LimitationsoftheTest:Bacterialcontaminationorrepeatedfreeze-thawcyclesofthespecimenmayaffecttheabsorbancevalues.ReferencesChristenssonA,LaurellCB,LiljaH.,EurJBiochem,194,755-63(1990).WattKW,et.al.,ProcNatAcadSciUSA,83,3166-70(1986).ChenZ,PrestiglacomoA,StameyT.,ClinChem,,41,1273-82(1995).WildD,TheImmunoassayHandbook.,StocktonPressp452(1994).JunkerR,BrandtB,ZechelC,AssmannG,ClinChem,43,1588-94(1997).PrestigiacomoAF,StameyTA,‘Physiologicalvariationsofserumprostateantigeninthe(4-10ng/ml)rangeinmalevolunteers.’J.Urol(1996);155:1977-80.StameyTA,McNealJE,YemotoCM,SigalBM,JohnstoneIM,‘BIOLOGicaldeterminantsofcancerprogressioninmenwithprostatecancer.’JAMA(19999;281:1395-1400.ChenZ,PrestigiacomoA,StameyT,‘PurificationandcharacterizationofProstateSpecificAntigen(PSA)Complexedtoa1-Anticymotrypsin:PotentialreferenceMaterialforInternationalStandardizationofPSAImmunoassays.’ClinChem.(1995);41/9:1273-1282.HortonGL,BahnsonRR,DattM,CfhanKM,CatalonaWJandLandensonJH.’DifferencesinvaluesobtainedwithtwoassaysofProstateSpecificAntigen.’J.Urol.(1988);139:762-72.StenmanUH,LeinonenJ,AlfthanH,RannikkoS,TuhkanenKandAlfthanO.’Acomplexbetweenprostatespecificantigenanda1-anticymotrypsinisthemajorformofprostatespecificantigeninserumofpatientswithprostatecancer:assayofcompleximprovesclinicalsensitivityforcancer.’CancerRes.(1991);51:222-26.AdditionalInformation:NameFreePSARelatedProductNamesFreePSAMolecularWeight0.5StorageTheclosedreagentsarestableuptotheexpirydatestatedonthelabelwhenstoredat+2…+8°Cinthedark.Openedreagentsarestablefor60dayswhenstoredat+2…+8°C.IntendedUseResearchUseOnly