Investigation of the STR loci noise distributions of PowerSeq™ Auto System

Aim To characterize the noise and stutter distribution of 23 short tandem repeats (STRs) included in the PowerSeq (TM) Auto System. Methods Raw FASTQ files were analyzed using STRait Razor v2s to display alleles and coverage. The sequence noise was divided into several categories: noise at allele position, noise at -1 repeat position, and artifact. The average relative percentages of locus coverage for each noise, stutter, and allele were calculated from the samples used for this locus noise analysis. Results Stutter products could be routinely observed at the -2 repeat position, -1 repeat position, and +1 repeat position of alleles. Sequence noise at the allele position ranged from 10.22% to 28.81% of the total locus coverage. At the allele position, individual noise reads were relatively low. Conclusion The data indicate that noise generally will be low. In addition, the PowerSeq (TM) Auto System could capture nine flanking region single nucleotide polymorphisms (SNPs) that would not be observed by other current kits for massively parallel sequencing (MPS) of STRs.