Forensic evaluation of VeriFiler™ Plus 6-dye chemistry kit composed of 23 loci with casework samples

Abstract

STR markers have been the genetic markers of choice in forensic DNA analysis for the past twenty years, and has proven to be an extremely discriminating method for human identification in forensics. In this study, I have evaluated a six-dye STR multiplex assay composed of 23 autosomal STR loci, 1 insertion/deletion polymorphic marker on the Y chromosome, Amelogenin and two internal quality control markers (IQCS and IQCL). This Internal validation indicated that VeriFilerTM Plus PCR amplification kit was reproducible, sensitive, accurate and robust. Sensitivity testing showed that a full profile can be obtained even with 63pg of human DNA. Heterozygous allele balance varied between 99-60 % for samples with total DNA input ranging from 1 ng to 500pg. It is also suitable for mixture study. All the alleles of minor contributor were called for ratios of 1:1, 1:3 and 3:1. overall this study demonstrate that VeriFilerTM Plus PCR amplification kit is robust, reliable and suitable as an assay for human identification with forensic casework samples.