Development and validation of a new STR 25-plex typing system.

Abstract In this study, a new STR 25-plex typing system, including 23 autosomal STRs (D1S1656, D2S1338, D2S441, D3S1358, D5S818, D6S1043, D7S820, D8S1179, D10S1248, D12S391, D13S317, D16S539, D18S51, D19S433, D21S11, D22S1045, CSF1PO, FGA, Penta D, Penta E, TH01, TPOX, vWA) and a Y-STR locus of DYS391 and amelogenin, was developed. The included 24 STRs belonged to the main international DNA databases (CODIS, ISSL, ESS-extended, UCL, GCL and NCIDD) except D6S1043 (specially chosen for Chinese population). Developmental validation indicated that the STR 25-plex typing system was reproducible, accurate, sensitive and robust. The sensitivity testing of the system was such that a full profile was obtainable even with 125pg of human DNA. Specificity testing was demonstrated by the lack of cross-reactivity with a variety of commonly encountered animal species and microbial pool. For the stability testing, full profiles can been obtained with humic acid concentration≤60ng/μL and hematin duo was 0.99999916563607 and CMEC tri was 0.99999999986525. All the forensic efficiency parameters demonstrated that this multiplex system is highly polymorphic and informative in the Han population of China.