Development and validation of a multiplex typing system with 32 Y-STRs for forensic application.

Y-chromosomal short tandem repeats (Y-STRs) with high mutation rates will increase the potential to distinguish related males and improve discrimination capacity. The newly developed Y32 kit is a six-dye multiplex amplification kit that contains 21 rapidly mutating Y-STR loci (DYF387S1a/b, DYF399S1a/b/c, DYF403S1a1/a2/a3/b, DYF404S1a/b, DYS449, DYS518, DYS526a/b, DYS547, DYS570, DYS576, DYS612, DYS626, and DYS627), 8 fast mutating Y-STR loci (DYS458, DYS464a/b/c/d, DYS516, DYS534, and DYS713), and 3 moderately mutating Y-STR loci (Y-GATA-A10, DYS630, and DYS446). To verify the efficiency and accuracy of the Y32 kit, PCR reaction conditions, sensitivity, mixture, concordance, inhibition, species specificity, case samples, reproducibility, sizing precision, stutter, and population study were studied according to the SWGDAM developmental validation guidelines. The results showed that the Y32 kit is efficient, accurate, reliable, and highly informative for forensic applications.