​Inthebloodstreamthemajorityofsteroidhormonesareboundeithertonon-specificproteinssuchasalbuminortospecificproteinssuchascorticosteroidbindingglobulin(CBG)orsexhormonebindingglobulin(SHBG). Theseproteinmoleculesaregenerallytoolargetodiffusefromthebloodstreamintothesalivaglands. Consequently,onlythe1-15%ofcirculatinghormonemoleculesthatarefoundinanunboundstatearefreetodiffusefrombloodintosaliva. Steroidhormoneconcentrationsinsalivaarethereforemuchlowerthanthoseinblood.Ifthebarrierbetweenthebloodstreamandtheoralmucosaiscompromisedbyinflammationormicroinjurysuchthatthereisleakageofbloodorplasmaintosaliva,thenthereisapossibilitythatthehigherlevelsofhormonesfoundinthebloodstreamwillcontaminatesalivasamples,causingfalselyhighreADIngs.(1)

Visualinspectionofsalivasamplesisnotadequatetodetectbloodcontamination,sincemicroinjuriestobloodvesselmembranesmayallowhormonemoleculesandproteinstopassthroughwhilestillretainingthemuchlargerredbloodcells. Dipsticktestsforblood,whichlookforthepresenceofhemoglobin,arealsonotareliablemeansofscreeningsalivasamples,duetothepresenceofperoxidasesinsaliva,whichcangeneratefalsepositiveresults.(2,3)

ThesalimetricsSalivaryBloodContaminationEnzymeImmunoassayquantitativelymeasurestransferrin,alargeprotein(molwt76,000)presentinabundanceinbloodthatisnormallypresentinonlytraceamountsinsaliva.  Higherlevelsoftransferrinmeasuredinsalivabythisassayindicatethepresenceofbloodcontaminationandserveasawarningtoinvestigatorsthatsamplesshouldbeexcludedfromsubsequentquantitativeassaysforsalivaryanalytesandstatisticalanalyses. (2,3,4) Salivasamplescollectedfrompopulationsthathavelittleornodentalcare,orknownoralhealthproblems,areespeciallyappropriateforscreeningwiththeBloodContaminationAssayKit.​

1. Malamud,D.,&Tabak,L.(Eds.).(1993). Salivaasadiagnosticfluid.AnnNYAcadSci,(Vol.694). NewYork,NY.
2. Kivlighan,K.T.,Granger,D.A.,Schwartz,E.B.,etal.(2004).Quantifyingbloodleakageintotheoralmucosaanditseffectsonthemeasurementofcortisol,dehydroepiandrosterone,andtestosteroneinsaliva. HormBehav,46(1),39-46.
3. Schwartz,E.,&Granger,D.A.(2004).Transferrinenzymeimmunoassayforquantitativemonitoringofbloodcontaminationinsaliva.ClinChem,50(3),654-656.
4. Granger,D.A.,Cicchetti,D.,Rogosch,F.,etal.(2007). Bloodcontaminationinchildren’ssaliva:Prevalence,stABIlity,andimpactonthemeasurementofsalivarycortisol,testosterone,anddehydroepiandrosterone. Psychoneuroendocrinology,32(6),724-33.