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Improved Methods for the Elution and Extraction of Spermatozoa From Sexual Assault Swabs

NCJ Number
224224
Journal
Forensic Magazine Volume: 5 Issue: 2 Dated: April/May 2008 Pages: 14,16,19,20,21
Author(s)
Robert C. Giles Ph.D.
Date Published
April 2008
Length
5 pages
Annotation
After reviewing the status of current methods for eluting spermatozoa from cotton swabs, this article reports on a series of experiments designed to increase the efficiency of recovery of spermatozoa from postcoital sexual assault samples.
Abstract
Orchid Cellmark has developed a proprietary sperm elution procedure that uses two buffer systems and increased physical agitation to remove sperm that has adhered to the cotton fibers of a swab. As a result, the procedure has shown an improvement in recovery of sperm from less than 10 percent using current elution methods to greater than 85 percent with the new optimized method. Using this new method, the eluted sperm pellet contains many fewer epithelial cells and thereby greatly enhances the ability of the forensic scientist to perform microscopic sperm searches much more rapidly. As an added feature of having fewer epithelial cells in the sperm pellet, the current research shows that the differential extraction process can now produce much cleaner male profiles even when the number of sperm available on the swab is less than 1,000. Producing cleaner cell populations with the new elution method has also led to studies that aim to reduce the incubation times required for differential extraction. These studies are currently being conducted and have produced promising results. It is feasible for this new method to be integrated with existing automation tools in reducing the already massive backlog of sexual assault cases in the United States. 1 table, 3 figures, and 8 references