Next generation sequencing-based precision STR genotyping of mixed samples / 中国法医学杂志

ABSTRACT

Objective To genotype mixed samples with next generation sequencing and evaluate its prospects in forensic DNA application. Methods Three mixed biological samples from rapes cases and their reference samples were collected. DNA was extracted using the MagAttract M48 DNA Manual Kit(200). The ForenSeqTMDNA Signature Prep Kit was used for library preparation, and next generation sequencing was performed on the MiSeq FGx system. The ForenSeqTMUniversal Analysis v1.2.1 software was used for data analysis. NGS-based STR results were compared with CE-based genotypes. Results A single length polymorphic STR allele in the mixed profile could be recognized as two sequence polymorphic STR alleles from different donors, which would assist mixed profile analysis. Such phenomenon was observed in D3S1358, D9S1122 and D13S317 in this work. Conclusion Our results suggested that precision STR genotyping of mixed samples based on NGS can provide more information and hints for mixed STR profile separation.