NCJ Number
189956
Journal
Canadian Society of Forensic Science Journal Volume: 34 Issue: 2 Dated: June 2001 Pages: 63-72
Date Published
June 2001
Length
10 pages
Annotation
This article reports on an evaluation of the commercially available OneStep ABAcard PSA test (Abacus Diagnostics, West Hills, CA) for the forensic identification of semen.
Abstract
Human semen samples (n=8) were collected from a local fertility clinic, and out-dated blood samples were collected from the Canadian Blood Services. Breast milk (n=6), saliva (n=10), and urine samples (n=10) were collected from volunteers. Where applicable, stains were prepared from these samples by depositing 200 ml of liquid on filter paper. Mixed stains represented 1:1 mixtures of the indicated body fluids. Dried stains were used in PSA assays. Sixteen postcoital swabs were donated by volunteers. The postcoital intervals varied from less than 24 hours to longer than 14 days. In addition, forensic case samples from routine sexual assault cases received at the RCMP Forensic Laboratory were analyzed in parallel to the established methodologies. A total of 109 samples from 46 cases were analyzed. The test was 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 after intercourse. Comparison of the results from the ABAcard to the acid fast blue test for acid phosphatase and the cross-over electrophoresis test for PSA revealed that the ABAcard test was more specific than the acid fast blue test and at least 100 times more sensitive than the cross-over technique. Evaluation of the ABAcard by using forensic case samples shows 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. 6 tables and 28 references