Abstract
X-chromosomal short tandem repeats are indispensable in specific cases, distinct from autosomal and Y chromosome genetic markers. SureID(®) X37 is an innovative six-colour fluorescence multiplex detection system that can simultaneously amplify 36 X-chromosomal short tandem repeat loci (including DXS6795, DXS7132, DXS8378, DXS10101, DXS10103, DXS10079, DXS10134, GATA165B12, GATA172D05, HPRTB, DXS6810, DXS10135, DXS6797, DXS10074, DXS7424, DXS9902, DXS7423, DXS10148, DXS10162, DXS6809, DXS10159, GATA31E08, DXS6803, DXS10075, DXS6807, DXS10164, DXS6789, DXS10146, DXS7133, DXS6804, DXS981, DXS9895, DXS101, DXS6800, DXS9907, and DXS8377) and the Amelogenin locus. In this study, we validated its suitability for forensic identification per Scientific Working Group on DNA Analysis Methods guidelines, including PCR conditions, precision, accuracy, case-type samples, sensitivity, repeatability, reproducibility, species specificity, stability, stutter calculation, and DNA mixtures. Additionally, 577 Chinese Han individuals were used to investigate the utility of the system in forensic population genetics. The results indicated that the system is sensitive, stable, and reliable and is suitable for typical forensic cases. Subsequent population investigations confirmed that it serves as a potent supplementary tool in forensic applications.