Speedy Rape Kit Analysis

In the United States, the backlog of unexamined rape kits has reached epic proportions. Many cases go unanalyzed simply due to time constraints, while others are neglected because of the inability, using current methods, to obtain a male profile from samples taken extended periods subsequent to the event for reasons such as the failure to report incidents involving acquaintances, when the perpetrator's administration of drugs renders the victim confused, or in cases involving children. In such instances, the male portion of the sample is overwhelmed by the female portion, and is often lost during the differential extraction procedure. To circumvent these technical difficulties, the addition of optimized Y-chromosome markers able to dissect a male profile out of a background of female material, obviating the need for a differential lysis, are an attractive option. We have developed two Y-STR multiplexes comprising 19 loci, and including the established 9 locus 'minimal haplotype.' Each of the systems yield a full male profile with as little as 200pg of template DNA, and can specifically amplify Y markers from mixed samples in male:female ratios up to 1:750. The two multiplexes, and subsets of the markers, are optimized to reduce X-chromosome artifacts, and have allowed us to amplify a male profile up to 4 days after intercourse with no interfering female amplimers. To aid with the speedy screening of large quantities of evidence, we are developing a direct lysis procedure followed by analysis using our Y-STRs to determine if male DNA is present.

For More Information

Jack Ballantyne
Department of Chemistry, CH 117
University of Central Florida
Orlando, FL 32816
Telephone: 407-823-0163
FAX: 407-823-2252
E-Mail: jballant@mail.ucf.edu