A 21-plex system of STRs integrated with Y-STR DYS391 and ABO typing for forensic DNA analysis

Abstract

The ABO blood group is considered to be one of the most important markers in forensic testing. Additionally, autosomal short tandem repeat (STR) genotyping continues to be recognized as the dominant technique for determination of human identity, and Y chromosome STR (Y-STR) analysis is becoming increasingly important in solving criminal cases. In this paper, we describe an integrated amplification system of ABO, autosomal STR, and Y-STR genotyping in a single reaction. This system allows for the simultaneous detection of 18 autosomal STR loci (13 Combined DNA Index System [CODIS] loci, as well as D2S1338, D6S1043, D12S391, Penta D, and Penta E), the ABO blood group locus, the Y-STR locus DYS391, and the sex-determining amelogenin locus. Primers were designed and optimized for amplicon sizes from 80–420 bp using a five-dye fluorescent design with the fifth dye reserved for the internal size standard. Sensitivity assays resulted in successful amplification of genomic DNA in the range of 0.250–2.000 ng. A total of 90 individuals from the Chinese Han population were studied using the system and forensic genetic data are presented. We conclude that this integrated system could be an updated and improved solution for forensic DNA analysis.