A validation study of a multiplex INDEL assay for forensic use in four Chinese populations

Insertion/deletion (INDELs) marker sets can serve as a useful supplementary tool for human identification. A commercial kit, the Qiagen DIPplex® Investigator kit, multiplexes 30 biallelic autosomal INDELs and Amelogenin for forensic use. We performed a validation study based on the DIPplex® kit in four Chinese populations: Han, Tibetan, Uyghur, and Kazakh. There were no significant departures from Hardy-Weinberg equilibrium or significant linkage disequilibrium (pair-wised r2 < 0.2) between the 30 INDELs. The random match probabilities were in the range of 3.84 × 10−11 to 1.20 × 10−12, and the power of exclusion was >0.99. The multiplex PCR was optimized for a 5-μL volume, full profiles were obtained with 0.062 ng/μL of template DNA, and excellent performance was obtained with degraded casework samples. This study demonstrates that the multiplex INDEL assay can be used as a supplementary method for degraded DNA detection in the studied Chinese populations.