Abstract: Objective We focus on developing a multiplex PCR system for Y-STR loci that can be detected by double fluorescent system and assessing their usefulness in forensic mixture samples. Methods The primers of four Y-STR loci (DYS-GATA-A10,DYS531,DYS557 and DYS448) amplified by multiplex PCR technique were labeled with fluorescence, then the PCR products of these Y-STRs loci were detecting and typing by ABI PRISM310 Genetic Analyzer. Results When 120 unrelated individuals from the Han population in Chengdu were detected by the system, Y-GATA-A10,DYS531,DYS557 and DYS448 showed 5, 5, 8, 7 alleles, respectively. A total of 78 different haplotypes was identified and the genetic diversity reached 0.9881.To the three cases of mixture stains failed by using conventional autosomal STR analysis, our multiplex system drew conforming conclusion comparing to the suspect′s Y-STRs genotypes. Conclusion Our results show that the multiplex system of four Y-STR will be very powerful for Y-STR database establishing, the paternity testing and mixture stains identifying.

Key words: Y-STR, Y-GATA-A10, DYS531, DYS557, DYS448, Primer labeled with fluorescence, multiplex PCR, mixture stains