Improved forensic DNA analysis through the use of alternative DNA polymerases and statistical modeling of DNA profiles
Improved forensic DNA analysis through the use of alternative DNA polymerases and statistical modeling of DNA profiles
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DOI：
10.2144/000113246
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发表时间：
2009-11-01
期刊：
影响因子：
2.7
通讯作者：
Radstrom, Peter
中科院分区：
文献类型：
--
作者：
Hedman, Johannes;Nordgaard, Anders;Radstrom, Peter
DNA证据将肇事者与犯罪现场联系在一起，是许多法律程序的核心。然而，犯罪现场的DNA样本通常含有聚合酶链式反应抑制物质，这可能会产生空白或不完整的DNA图谱。尽管这些程序增加了DNA丢失的风险，但可能需要广泛的DNA纯化来去除样本中的这些抑制剂。大多数法医实验室使用商用DNA扩增试剂盒(例如，AmpFlSTR SGM Plus)，以DNA聚合酶AmpliTaq Gold为金标准。在这里，我们表明，替代的DNA聚合酶-缓冲系统可以提高法医DNA分析的质量，并有效地绕过犯罪现场样本中的PCR抑制，而不需要额外的样本准备。使用Bio-X-Act Short、ExTaq hotStart或PicoMaxx High Fidelity替代AmpliTaq Gold，32个完全或部分被抑制的犯罪现场唾液样本中的20个的DNA图谱显著改善。建立了法医DNA图谱无偏质量控制的统计模型，对结果进行了量化。我们的研究证明了调整聚合酶链式反应的化学成分以加强法医DNA分析和诊断聚合酶链式反应的重要性，提供了一种替代繁琐的样品制备方法的方法。
DNA evidence, linking perpetrators to crime scenes, is central to many legal proceedings. However, DNA samples from crime scenes often contain PCR-inhibitory substances, which may generate blank or incomplete DNA profiles. Extensive DNA purification can be required to rid the sample of these inhibitors, although these procedures increase the risk of DNA loss. Most forensic laboratories use commercial DNA amplification kits (e.g., AmpFlSTR SGM Plus) with the DNA polymerase AmpliTaq Gold as the gold standard. Here, we show that alternative DNA polymerase-buffer systems can improve the quality of forensic DNA analysis and efficiently circumvent PCR inhibition in crime scene samples, without additional sample preparation. DNA profiles from 20 of 32 totally or partially inhibited crime scene saliva samples were significantly improved using Bio-X-Act Short, ExTaq Hot Start, or PicoMaxx High Fidelity instead of AmpliTaq Gold. A statistical model for unbiased quality control of forensic DNA profiles was developed to quantify the results. Our study demonstrates the importance of adjusting the chemistry of the PCR to enhance forensic DNA analysis and diagnostic PCR, providing an alternative to laborious sample preparation protocols.