Development and Forensic Application of EX20+30Y Kit.

Abstract

To develop a multiplex PCR amplification system (EX20+30Y for short) of 19 autosomes, 30 Y-STR loci plus the gender indicator, and evaluate its forensic application value. With the six-color fluorescence labeling technology, a multiplex amplification system of 19 autosomal STR loci and 30 Y-STR loci plus the gender indicator was constructed. Blood samples from 210 unrelated individuals, 69 daily case samples and standard samples 9948 and 9947A were collected for loci detection and analysis. The EX20+30Y multiplex amplification system was evaluated by its sensitivity, mixed sample detection ability, species specificity, balance, direct amplification ability, sample applicability and anti-inhibition ability. Multiplex amplification of blood samples from 210 unrelated individuals by the detection system obtained accurate genotyping results. The detection sensitivity of standard samples was 0.125 ng and the species specificity was high. The 69 samples from daily cases were genotyped correctly. Moreover, standard sample 9948 could be accurately genotyped even if the samples contained a certain concentration of inhibitors. The multiplex amplification system established in this study can conduct combined examination of 19 autosomes, 30 Y-STR loci plus the gender indicator with accurate genotyping and high sensitivity. It has a good forensic application prospect.