Department of Forensic Medicine, Seoul National University College of Medicine, Seoul, South Korea.
Institute of Forensic and Anthropological Science, Seoul National University College of Medicine, Seoul, South Korea.
Electrophoresis. 2024 Oct;45(19-20):1805-1819. doi: 10.1002/elps.202400037. Epub 2024 Aug 9.
The identification of tissue-specific differentially methylated regions has significantly contributed to the field of forensic genetics, particularly in body fluid identification crucial for linking evidence to crimes. Among the various approaches to analyzing DNA methylation, the SNaPshot assay has been popularly studied in numerous researches. However, there is a growing interest in exploring alternative methods such as the use of massively parallel sequencing (MPS), which can process a large number of samples simultaneously. This study compares SNaPshot and MPS multiplex assays using nine cytosine-phosphate-guanine markers for body fluid identification. As a result of analyzing 112 samples, including blood, saliva, vaginal fluid, menstrual blood, and semen, both methods demonstrated high sensitivity and specificity, indicating their reliability in forensic investigations. A total of 92.0% samples were correctly identified by both methods. Although both methods accurately identified all blood, saliva, and semen samples, some vaginal fluid samples showed unexpected methylation signals at nontarget loci in addition to the target loci. In the case of menstrual blood samples, due to their complexity, independent typing criteria were applied, and successful menstrual blood typing was possible, whereas a few samples showed profiles similar to vaginal fluid. The MPS method worked better in vaginal fluid samples, and the SNaPshot method performed better in menstrual blood samples. This study offers valuable insights into body fluid identification based on the characteristics of the SNaPshot and MPS methods, which may help in more efficient forensic applications.
组织特异性差异甲基化区域的鉴定极大地促进了法医遗传学领域的发展，特别是在鉴定与犯罪有关的体液证据方面至关重要。在分析 DNA 甲基化的各种方法中，SNaPshot 检测法在许多研究中得到了广泛的研究。然而，人们越来越感兴趣地探索替代方法，如使用能够同时处理大量样本的大规模平行测序（MPS）。本研究比较了 SNaPshot 和 MPS 多重检测法，使用 9 个胞嘧啶-磷酸-鸟嘌呤标记物进行体液鉴定。通过分析包括血液、唾液、阴道液、月经血和精液在内的 112 个样本，两种方法均表现出高灵敏度和特异性，表明它们在法医调查中的可靠性。两种方法总共正确识别了 92.0%的样本。尽管两种方法都准确地识别了所有的血液、唾液和精液样本，但一些阴道液样本除了目标位点外，还显示出非目标位点的意外甲基化信号。在月经血样本的情况下，由于其复杂性，应用了独立的分型标准，并且可以成功进行月经血分型，而少数样本显示出与阴道液相似的图谱。MPS 方法在阴道液样本中的效果更好，而 SNaPshot 方法在月经血样本中的效果更好。本研究提供了基于 SNaPshot 和 MPS 方法特征的体液鉴定的有价值的见解，这可能有助于更高效的法医应用。
