Evaluation of the PowerSeq™ Auto System by Massively Parallel Sequencing

Short tandem repeats (STRs) are the primary genetic markers used in forensic DNA human identification testing, due to their high discrimination power and relatively short amplicon size. Currently, multiplex amplification with fluorescent tagging and capillary electrophoresis (CE) are employed for STR typing. However, CE-based methods have some limitations: limited number of STR loci can be typed simultaneously, stutter issues, and fluorescent artifacts. Massively parallel sequencing (MPS) technologies allow for a substantial increase in throughput and depth of coverage at a relatively affordable price. Previously, studies indicated that MPS is another potential technology for STR typing by forensic laboratories and that some of the CE-based limitations may be overcome by MPS. STR amplicons can be engineered in size to be better suited for analyzing degraded samples, and more STR loci can be multiplexed. Moreover, intraSTR SNPs can be revealed to increase discrimination power, and stutter products may be distinguished from minor contributor alleles in mixtures.