The research was based on the analysis of mock forensic case samples that included various biological samples from individuals at the MFSL. To address the validation of standard specimens, DNA was isolated from semen, vaginal secretions, saliva, urine, and blood samples. Typing results from all tissues from a particular individual yielded the same typing results using both DQA1 and Polymarker systems. Reproducibility between laboratories was evaluated by having duplicate samples analyzed by a second laboratory. All typing results from both laboratories for approximately 30 single source samples were in agreement. Mixed specimens were evaluated by examining results obtained from semen/vaginal, semen/saliva, semen/blood, semen/urine, and semen/vaginal/blood mixtures. All typing results from both laboratories for these mixtures were in agreement. It was determined that, by incorporating a wash step of the sperm cell pellet, a complete separation of the nonsperm cell fraction was more likely to be attained. 20 references and 3 tables