Developmental validation of the EX20+4 system

The EX20+4Y System is a polymerase chain reaction (PCR)-based amplification kit that enables typing of 19 autosomal short tandem repeat (STR) loci (i.e., CSF1PO, D13S317, D16S539, D18S51, D21S11, D3S1358, D5S818, D7S820, D8S1179, FGA, TH01, TPOX, vWA, Penta D, Penta E, D2S1338, D19S433, D12S391, D6S1043), four widely used Y chromosome-specific STR (Y-STR) loci (DYS458, DYS456, DYS391, DYS635), and amelogenin. In this study, this multiplex system was validated for sensitivity of detection, DNA mixtures, inhibitor tolerance, species specificity based on the Scientific Working Group on DNA Analysis methods (SWGDAM) developmental validation guidelines, and the Chinese criteria for the human fluorescent STR multiplex PCR reagent. The results show that the EX20+4 System is a robust and reliable amplification kit which can be used for human identification testing.