Evaluation of the Investigator 26plex QS and SureID PanGlobal systems in forensic analysis and comparison with commonly used NGM PCR Amplification Kit

Abstract

The aim of the study was to evaluate the novel kits – Investigator 26plex QS and SureID PanGlobal in forensic analysis and confront with commonly applied NGM PCR Amplification Kit. The internal validation study involved sensitivity, reliability, stochastic, DNA mixtures, inhibition parameters analysis and 15 casework samples extracted from blood, saliva, semen, tooth, bones, soft tissue and epithelial cells. The sensitivity experiments were performed on a total of 24 samples from seven serial dilutions of 007 control DNA. Mixture analysis was performed for two persons in different proportions using 9947 and 007 control DNA. Inhibition effect was tested using PCR inhibitor – humic acid. Among three compared kits the highest sensitivity was noted for Investigator 26plex QS considering the total number of the markers in each system, as well as the shared set of markers. However, low PCR efficiency of D6S1043 locus was observed with aforementioned kit. Mixture analysis performed with Investigator 26plex QS, SureID Pan Global and NGM kits, considering shared set of markers revealed that NGM Kit is the most sensitive for detecting minor components in a mixture. Similarly, we demonstrated that NGM is the most successful in the analysis of challenging forensic samples. The internal validation showed that the Investigator 26plex QS and SureID PanGlobal have weaker performance for routine forensic application in comparison to NGM Kit. However, thanks to increased number of markers, these systems could be helpful in analysis of complex cases in paternity testing and kinship analysis, in which standard genetic analysis is insufficient.