validationstudy of the. "onestepabacard@psa test" kit for rcmp

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Can. Soc. Forero. Sci. J. Vol. 34. No 2 (2001) pp. 63-72
VALIDATIONSTUDY OF THE.
"ONESTEPABACARD@PSA TEST" KIT FOR
RCMP CASEWORK
J. KEARSEyl, H. LOUIE! AND H, POONl,2
ABSTRACT
The commercially available OneStep A8Acard~ PSA test (Abacus Diagnostics, West
Hills, CA) was evaluated for the forensic Identification of semen. The test Is shown
to have a sensitivity of 4 ng/mL PSA. No detectable levels of PSA were Identified in
saliva, blood, or female urine. As expected, liquid urine from male donors yielded
positive results. Furthermore, PSA was detected In the vagina for at least 24 hours
atter Intercourse. Comparison of the results from the A8Acard~ to the acid fast blue
test for acid phosphatase and the cross-over electrophoresis test for PSA reveals
that the ABAcardi!Jtest is more specific than the acid fast blue test and at least one
hundred times more sensitive than the cross-over technique. Evaluation of the
ABAcard@ using forensic case samples revealed that it is appropriate for forensic
use on samples to be subsequently examined by DNA analysis. The OneStep
ABAcard~ PSA test was shown to be reliable, sensitive, and specific, and therefore
appropriate for forensic application in the identification of semen.
RESUME
Le test One Step ABAcard@ PSA, provenant de la compagnie Abacus Diagnostics
(West Hills, CA) a ete evalue pour I'ldentification de sperme en milieu judlcialre. Une
sensibllite de 4 ng/mL pour la PSA ("prostate specific antigen") a ete demontree
pour ce test. Aucune proteine PSA en quantlte detectable n'a ete Identlflee dans la
salive, Ie sang ou I'.urine d'orlglne feminine, Comme prevu, des resultats positifs
furent obtenus avec des echantilions d'urine IIqulde provenant de donneurs males.
De plus, de la PSA fut detectee dans des echantilions vaglnaux obtenus dans un
interval post-co'ftal de 24 heures. Une comparaison des resultats obtenus avec Ie
test ABAcardi!J, Ie test pour la phosphatase acide (FAST BLUE) et I'electrophorese
cross-over demontre que Ie test ABAcard@ est plus specifique que Ie test FAST
BLUE et au moins 100 fois plus sensible que la technique d'electrophorese crossover,'Une evaluation du test ABAcard@avec des echantillons judiciaires destines a
I'analyse d'ADN demontre que ce test est parfaitement approprie, Cette etude con..
firme donc que Ie test ABAcard@ est fiable, sensible et specifique et parfaitement
adequat a une application en milieu judlcialre pour I'identificatlon de sperme.
INTRODUCTION
Identification of semen in sexual assaultcasesoften provides sufficient evidence that
sexual contact between the parties involved has occurred, Semen is typically KJentified
microscopically by the presenceof spermatozoa.However, in caseswhere little or no spermatozoa are d~tected,testsfor acid phosphatase(1) or prostatespecific antigen (2) (PSA,
1.
2.
BiologySection,ForensicLaboratoryVancouver,RoyalCanadianJylo\J,nted
Police.5201HeatherStreet,
Vancouver,B.C. V5Z 3L7.
To whomcorrespondence
shouldbeaddressed.
63