Mayes Carrie, Houston Rachel, Seashols-Williams Sarah, LaRue Bobby, Hughes-Stamm Sheree
Department of Forensic Science, College of Criminal Justice, Sam Houston State University, 1003 Bowers Blvd., Huntsville, TX 77340-2525, United States.
Department of Forensic Science, College of Criminal Justice, Sam Houston State University, 1003 Bowers Blvd., Huntsville, TX 77340-2525, United States.
Leg Med (Tokyo). 2019 May;38:45-50. doi: 10.1016/j.legalmed.2019.03.007. Epub 2019 Mar 28.
The identification of body fluids in evidentiary stains may provide investigators with probative information during an investigation. In this study, quantitative reverse transcription polymerase chain reaction (RT-qPCR) assays were performed to detect the presence of mRNA and miRNA in fresh and environmentally challenged samples. Blood, semen, and reference markers were chosen for both mRNA/miRNA testing. Samples of blood and semen were exposed to heat, humidity, and sunlight, and controlled conditions (room temperature, low humidity, and darkness) for 6 months. All mRNA targets were observed through six months under controlled conditions, but were undetected after 30 days in experimental conditions. However, miRNA targets persisted under all test conditions for the duration of the study. Additionally, cotton stained with blood or semen was laundered using a liquid detergent in various washing and drying conditions. An unstained cutting was evaluated for potential transfer. Both miRNA targets were observed in all stained samples regardless of the wash protocol used. Of the mRNA markers, HBB was detected in all bloodstained samples and PRM1 persisted in all but one semen stained sample. The unstained samples showed transfer of at least one body fluid specific miRNA marker in all samples and at least one body fluid specific mRNA in approximately half of the samples. These results support that RNA markers can be used for body fluid identification in challenging samples, and that miRNA markers may be more persistent than mRNA for blood and semen stains. However, some caution is warranted with laundered items due to possible transfer.
在调查过程中，鉴定证据污渍中的体液可为调查人员提供具有证明力的信息。在本研究中，进行了定量逆转录聚合酶链反应（RT-qPCR）分析，以检测新鲜样本和受环境影响样本中mRNA和miRNA的存在。选择血液、精液和参考标志物进行mRNA/miRNA检测。将血液和精液样本暴露于高温、高湿度和阳光下，并在受控条件（室温、低湿度和黑暗）下放置6个月。所有mRNA靶点在受控条件下6个月内均可观察到，但在实验条件下30天后未检测到。然而，在研究期间，miRNA靶点在所有测试条件下均持续存在。此外，用液体洗涤剂在各种洗涤和干燥条件下清洗沾有血液或精液的棉花。对一块未染色的布料进行潜在转移评估。无论使用何种洗涤方案，在所有染色样本中均观察到两种miRNA靶点。在mRNA标志物中，所有血渍样本中均检测到HBB，除一个精液染色样本外，PRM1在所有精液染色样本中均持续存在。未染色样本在所有样本中均显示至少一种体液特异性miRNA标志物的转移，在大约一半的样本中显示至少一种体液特异性mRNA的转移。这些结果支持RNA标志物可用于鉴定具有挑战性的样本中的体液，并且对于血液和精液污渍，miRNA标志物可能比mRNA更持久。然而，由于可能存在转移，对于洗涤过的物品需要谨慎对待。
