Department of Forensic Science, Sam Houston State University, Huntsville, TX, USA.
Verogen Inc, San Diego, CA, USA.
J Forensic Sci. 2021 Sep;66(5):1929-1936. doi: 10.1111/1556-4029.14763. Epub 2021 May 31.
Rootless hair shafts are often considered unsuitable for STR genotyping due to the known high failure rate. The same samples can be reliably processed with mitochondrial sequencing. However, the minimal discriminatory power of widely implemented control region mitochondrial sequencing techniques limits its utility in some forensic casework. In this research, multiple variables were tested to provide information on rootless hair shaft sample genotyping success. Results showed external decontamination procedures decreased drop-in alleles but also greatly reduced profile recovery. The novel InnoXtract chemistry was comparable to automated EZ1 DNA Investigator extraction. With thoroughly decontaminated hairs, InnoTyper 21 amplification generated random match probabilities higher than STR chemistry in 71.875% of samples and 18.75% of samples benefitted from the use of InnoTyper 21 amplification compared with estimated mtDNA profile rarity. Compared with the capillary electrophoresis-based amplification chemistries tested, the ForenSeq™ DNA Signature Prep chemistry paired with massively parallel sequencing was the most discriminatory amplification strategy tested.
无毛囊的头发由于已知的高失败率，通常不适合 STR 基因分型。相同的样本可以通过线粒体测序可靠地处理。然而，广泛实施的控制区线粒体测序技术的最小鉴别能力限制了其在某些法医工作中的应用。在这项研究中，测试了多个变量，以提供有关无毛囊头发样本基因分型成功的信息。结果表明，外部去污程序降低了插入等位基因的数量，但也大大降低了谱带恢复的数量。新型的 InnoXtract 化学物质与自动化 EZ1 DNA Investigator 提取物相当。经过彻底去污的头发，InnoTyper 21 扩增在 71.875%的样本中产生的随机匹配概率高于 STR 化学物质，在 18.75%的样本中，与估计的 mtDNA 谱带稀有性相比，使用 InnoTyper 21 扩增获益。与测试的基于毛细管电泳的扩增化学物质相比，与大规模平行测序相结合的 ForenSeq™ DNA Signature Prep 化学物质是测试的最具鉴别力的扩增策略。
