First experiences using the new Powerplex® ESX17 and ESI17 kits in casework analysis and allele frequencies for two different regions in Germany

DNA databases are the most efficient tools in criminal investigations with unknown perpetrators. Due to a significant number of random matches in cross-border DNA profile exchanges, the European Network of Forensic Science Institutes (ENFSI) proposed the addition of further short tandem repeats (STRs) to European DNA databases. Therefore, the new Powerplex® ESX17 and Powerplex® ESI17 kits from Promega comprised the 11 established DNA database STRs and additionally the well-known loci D1S1656 and D12S391, as well as D2S441, D10S1248, and D22S1045. The latter three STRs are thereby established as so-called mini-STRs to fulfill the increasing requirements regarding sensitivity and reproducibility for analysis of minute amounts of DNA. Here, we provide allele frequencies for the five additional STRs from two populations from Germany. A test regarding suitability and robustness of the new kits for routine trace analysis showed that it is more likely to obtain a meaningful profile using Powerplex® ESX17 and Powerplex® ESI17 kits compared to the Powerplex® ES kit. However, for both new kits the range of template DNA amount is rather small, e.g., slightly more DNA than recommended resulted in DNA profiles which could not be reliably evaluated due to allelic drop-in or imbalances and overshoots. In our opinion, the new kits are very promising new tools in forensic trace analysis even though handling and evaluation should yet be carried out with great caution.