Forensic validation of the PowerPlex® ESI 16 STR Multiplex and comparison of performance with AmpFlSTR® SGM Plus®

We describe the forensic validation of Promega's PowerPlex® European Standard Investigator 16 (ESI 16) multiplex kit and compare results generated with the AmpFlSTR® SGM Plus® (SGM+) multiplex. ESI 16 combines the loci contained within the SGM+ multiplex with five additional loci: D2S441, D10S1248, D22S1045, D1S1656, and D12S391. A relative reduction in amplicon size of the SGM+ loci facilitates an increased robustness and amplification success of these amplicons with degraded DNA samples. Tests performed herein supplement ESI 16 data published previously with sensitivity, profile quality, mock casework, inhibitor and mixture study data collected in our laboratories in alignment with our internal technical and quality guidelines and those issued by the Scientific Working Group on DNA Analysis Methods (SWGDAM), the DNA Advisory Board (DAB) and the DNA working group (DNAWG) of the European Network of Forensic Science Institutes (ENFSI). Full profiles were routinely generated from a fully heterozygous single source DNA template using 62.5 pg for ESI 16 and 500 pg for SGM+. This increase in sensitivity has a consequent effect on mixture analyses and the detection of minor mixture components. The improved PCR chemistry confers enhanced tolerance to high levels of laboratory prepared inhibitors compared with SGM+ results. In summary, our results demonstrate that the ESI 16 multiplex kit is more robust and sensitive compared with SGM+ and will be a suitable replacement system for the analysis of forensic DNA samples providing compliance with the European standard set of STR loci.