Chemistry Department, University at Albany, SUNY, 1400 Washington Ave, Albany, NY 12222, United States.
Chemistry Department, University at Albany, SUNY, 1400 Washington Ave, Albany, NY 12222, United States.
Talanta. 2019 Mar 1;194:385-389. doi: 10.1016/j.talanta.2018.10.034. Epub 2018 Oct 17.
Semen evidence can be of critical importance in assault cases. In the past, semen confirmatory tests relied solely on the presence of sperm. However, current semen tests rely on the detection of proteins in the seminal fluid because some semen contains no sperm, a condition called azoospermia. Our laboratory has been developing a Raman spectroscopic test for identification of dry traces of body fluids, including semen, for forensic purposes. An automatic software has already been built for differentiating all the main body fluids (Muro et al., 2016). The main objective of this study was to evaluate the ability of Raman spectroscopy to identify semen traces in the absence of sperm. For this purpose, a comparative analysis of Raman spectra of semen, seminal fluid and sperm samples obtained from several donors was conducted. It was determined that the contribution of seminal fluid dominates the Raman spectra of semen. This was further confirmed by analyzing Raman spectra of semen obtained from a donor who had had a vasectomy. All of the individual spectra from seminal fluid and azoospermatic semen were correctly identified with a previously made chemometric model as semen. It was concluded that the presence of sperm is not necessary for the correct identification of semen using Raman spectroscopy and chemometrics. This further demonstrates the great potential of Raman spectroscopy as a universal tool for confirmatory identification of all main body fluids for forensic purposes.
精液证据在攻击案件中可能至关重要。过去，精液确认测试仅依赖于精子的存在。然而，目前的精液测试依赖于精液中蛋白质的检测，因为有些精液中没有精子，这种情况称为无精症。我们的实验室一直在开发一种用于鉴定法医干燥体液痕迹（包括精液）的拉曼光谱测试。已经为区分所有主要体液（Muro 等人，2016 年）构建了一个自动软件。本研究的主要目的是评估拉曼光谱在没有精子的情况下识别精液痕迹的能力。为此，对从几个供体获得的精液、精浆和精子样本的拉曼光谱进行了比较分析。结果表明，精浆的贡献主导了精液的拉曼光谱。通过分析输精管切除术供体获得的精液的拉曼光谱进一步证实了这一点。所有来自精浆和无精症精液的个体光谱都使用以前制作的化学计量模型正确识别为精液。结论是，使用拉曼光谱和化学计量学正确识别精液不需要精子的存在。这进一步证明了拉曼光谱作为法医确认鉴定所有主要体液的通用工具的巨大潜力。
