Validation of the Microreader™ 36A ID System for forensic genetic casework and database construction

Autosomal short tandem repeats (STRs) are crucial in identifying humans. Herein, a developmental validation was performed for a newly generated autosomal STR kit (Microreader™ 36A ID System). The sensitivity of this kit was fine when the input DNA dropped down to 0.02 ng/uL. Mixture analysis showed that when male:female = 200 pg: 5400 pg, full profiles of both individuals could be obtained. When inhibited substances existed, all alleles were acquired up to 2000 μM haematin, 1000 ng/μL humic acid or 250 ng/μL tannic acid. The kit exhibited a high precision level with no more than 0.29 nt standard deviation of allele size, with the accuracy (the difference of allele size between the true allele and ladder allele) no more than 0.4 nt. The total discrimination power of this system in the Chinese Han and Hui population was larger than 1–0.1 × 10⁻³⁰. For the full-sibling test, the identical-by-state (IBS) score varied from 37 to 46, while it was from 21 to 28 when using the AGCU Express marker 22 STR Kit. This kit can increase the autosomal STR information of a single PCR reaction and is promising in the casework of forensic genetic as well as database construction.