The study found that the Plexor HY System reliably and simultaneously quantified total human and male DNA from single-source and mixture samples. The system demonstrated good correlation between inhibition of autonomic and Y quantification amplifications and changes in the IPC Ct value. The quantification of both total human and male DNA in complex forensic samples provides critical information on how to proceed with sample analysis. Quantification must consistently suggest an appropriate amount of sample in order to produce interpretable STR results. This information must be generated with minimal sample consumption and confidently identify samples with inadequate amounts of DNA for STR analysis. Quantification must not be significantly affected by the presence of contaminating DNA, and the quantification system must provide adequate controls to flag partial and complete inhibition that affects quantification results. The validation studies examined human specificity, sensitivity, quantification of degraded DNA, impact of inhibitors, male/female mixture and Y-assay male specificity, reproducibility and concordance, and population studies. The descriptions of materials and methods address the characteristics of the tested DNA, real-time PCR cycling and detection, Plexor data analysis, inhibitors, and STR analysis. 2 tables, 5 figures, and 23 references