Comparison and Internal Validation of GlobalFiler™, VeriFiler™, and Investigation® 24Plex PCR Kits in Forensic DNA Identification

Abstract

In the forensic biology laboratory, an internal validation process is performed to determine the reliability and reproducibility of an identification kit. STR kits, which are used for identification with DNA are commercially produced by various companies. Due to primary design differences by the companies, there may be differences in the performance of STR loci in the kits depending on the devices used in the laboratory. The main purpose of this study is to determine which kits are the most ideal and reliable in terms of reproducibility and accuracy of results. In this study, positive control samples included in the kit and fingertip blood, hair and buccal swab samples obtained from 4 volunteer laboratory personnel were used. After DNA isolation and quantification, PCR amplification was performed with GlobalFiler™, VeriFiler™ Plus and Investigator® 24plex QS PCR Amplification Kit. Amplicons were electrophoresed in 3130xl Genetic Analyzer and analyzed with GeneMapper ID-X v1.5. DNA materials from blood, hair and buccal swap samples of volunteers were tested. Full analyzable profiles were obtained with 1–0.25 ng/µl. Drop outs were observed in the alleles obtained with 0.0625 ng/µl DNA. The results obtained from these kits were complementary to each other. Optimization studies are planned for future studies on forensic DNA identification analysis from crime scene samples such as bones, teeth and semen.