Validation of SRY Marker for Forensic Casework Analysis

Determining the gender of the source of forensic DNA evidence is based on the amelogenin test. However, at times the assay may not be indicative of gender assignment, because of deletions at the amelogenin site. Previously, we described successful coamplification of a marker residing within the SRY gene with the short tandem repeat markers from two commercially available human identification kits. The study herein addresses the validation of primers for the target SRY gene regarding specificity, sensitivity, and robustness. Among 115 unrelated male Slovenians no null allele was observed. Repeatable and reliable results were obtained from as little as 25 pg of template DNA, indicating a high sensitivity of detection for the assay. No polymerase chain reaction product was observed even at a concentration of 10 ng/L of template female DNA. Additionally, the male specific marker could be detected in mixed male and female samples down to a ratio of 1:16.