Results of the study show that both approaches tested produced linear estimates for DNA quantity over a broad range of input DNA. The study tested to systems: Quantifiler Duo, a system that utilizes a TaqMan assay with single copy probes for both autosomal human and Y quantification, and Plexor HY, a system that utilizes a primer quenching assay with multi-copy probes for its quantification of autosomal human and Y-chromosomal DNA. The NIST Human DNA Quantification Standard Reference Material 2372, a set of three different NIST human DNA quantification standards, was used to examine the precision, accuracy, and sensitivity of the real-time PCR assays. The overall results of the analyses found that the single copy approach, Qualifier Duo, provided better accuracy while the multi-copy approach, Plexor HY, produced better sensitivity. These results indicate that the choice of which system to use for the determination of relative quantities of autosomal and Y-chromosomal DNA using real-time PCR depends upon the goals of the user. Tables, figures, and references