Kristy Lenz, Dawn Rabbach, Chao Liu, Quyi Xu, Ying Zeng,, Douglas Storts
The VersaPlex™ 27PY System is an STR multiplex from Promega offering co-amplification of 27 loci. This six-dye multiplex was designed for casework samples and includes loci that meet database requirements for the US (CODIS), Europe (ESS) and China (Chinese National Database). The 23 autosomal loci include the D6S1043 locus because of its high level of discrimination power, especially in Asian populations. The multiplex also includes two rapidly-mutating Y-STRs that can provide useful genetic information for forensic samples. In this article we describe the developmental validation experiments performed on the VersaPlex™ 27PY System that were designed to meet SWGDAM requirements. Changes in the performance of the multiplex are documented in response to reaction variables including PCR inhibitors, reaction volume, cycle number, annealing temperature, and magnesium concentration. The sensitivity, specificity, precision, and reproducibility of the VersaPlex™ 27PY System were also evaluated. The results of the experiments demonstrate the capabilities of the VersaPlex™ 27PY System as a tool for forensic laboratories.