Developmental validation of VeriFiler™ Plus PCR Amplification Kit: A 6-dye multiplex assay designed for casework samples

Abstract

The VeriFiler™ Plus PCR Amplification Kit is a 6-dye multiplex assay that simultaneously amplifies a set of 23 autosomal markers (D3S1358, vWA, D16S539, CSF1PO, D6S1043, D8S1179, D21S11, D18S51, D5S818, D2S441, D19S433, FGA, D10S1248, D22S1045, D1S1656, D13S317, D7S820, Penta E, Penta D, TH01, D12S391, D2S1338, and TPOX), a quality indicator system, and two sex-identification markers. Combined, the markers satisfy the requirements of the Chinese National autosomal DNA database as well as expanded CODIS (Combined DNA Index System). The VeriFiler Plus kit was developed with an improved Master Mix which incorporates the brighter TED™ dye, and accommodates a higher sample loading volume thus allowing for increased sensitivity and enabling maximum information recovery from challenging casework samples including touch, degraded, and inhibited samples. Here, we report the results of the developmental validation study which followed the SWGDAM (Scientific Working Group on DNA Analysis Methods) guidelines and includes data for PCR-based studies, sensitivity, species specificity, stability, precision, reproducibility and repeatability, concordance, stutter, DNA mixtures, and performance on mock casework samples. The results validate the multiplex design as well as demonstrate the kit's robustness, reliability, and suitability as an assay for human identification with casework DNA samples.

Keywords: CODIS; Casework samples; Chinese National Database; Forensic validation studies; Human identification; Multiplex PCR assay; STR; VeriFiler™ Plus Kit.