Developmental validation of a complementary Y-STR system for the amplification of forensic samples

In this study, a new complementary Y-STR system that includes 31 loci was developed (DYS522, DYS388, DYF387S1a/b, DYS510, DYS587, DYS645, DYS531, DYS593, DYS617, GATA_A10, DYS622, DYS552, DYS508, DYS447, DYS527a/b, DYS446, DYS459a/b, DYS444, DYS557, DYS443, DYS626, DYS630, DYS526a, DYF404S1a/b, DYS520, DYS518, and DYS526b). This 31-plex Y-STR system, SureID® Y-comp, is designed for biological samples from forensic casework and reference samples from forensic DNA database. To validate the suitability of this novel kit, many developmental works including size precision testing, sensitivity, male specificity testing, species specificity, PCR inhibitors, stutter precision, reproducibility, suitability for use on DNA mixture and parallel testing of different capillary electrophoresis devices were performed. Mutation rates were investigated using 295 DNA-confirmed father-son pairs. The results demonstrate that the SureID® Y-comp Kit is time-efficient, accurate, and reliable for various case-type samples. It possessed a higher discrimination power and can be a stand-alone kit for male identification. Moreover, the simply acquired additional Y-STR loci will be conductive to construct a robust database. Even if various commercial Y-STR kits are used in distinct forensic laboratories, a wider trans-database retrieval will become feasible with the effort of the SureID® Y-comp Kit.