Conte Jillian, Ruddy Ashley, Domonoski Lindsey, Shanahan Aubrey, Daley Natalie, McDevitt Colleen, Roca Gabriela
Keystone College, La Plume, Pennsylvania, USA.
MicroGEM US, Charlottesville, Virginia, USA.
J Forensic Sci. 2022 May;67(3):1176-1183. doi: 10.1111/1556-4029.14999. Epub 2022 Feb 18.
There is an increased use of immunochromatographic test strips to presumptively identify bodily fluids of forensic interest, such as blood, semen, and saliva. Commonly, forensic samples are of low quantities. In the practice of conserving limited samples, it would be ideal to be able to recover the genetic material deposited on these testing membranes. This research aimed to determine whether DNA could be extracted from semen and saliva test strips, which part of the test strip is best to use, and to assess the quality of the DNA recovered. Semen and saliva samples were deposited on SERATEC PSA Semiquant and Amylase Tests and analyzed. The testing membrane was then removed from the cassette and DNA extraction methods (forensicGEM Universal, forensicGEM Sperm, QIAamp DNA Mini kit, Monarch Nucleic Acid Purification kit, and organic extraction) were performed. Quality was evaluated by qPCR and STR analysis. DNA from semen was best extracted using the Monarch Nucleic Acid Purification kit, while saliva was best extracted using the forensicGEM or QIAamp kits. No significant differences were observed between collection of the sample well pad and testing strip, thus use of the entire strip is encouraged. DNA from semen and saliva was quantifiable with a 1:1000 dilution. DNA quality analysis by qPCR showed that there is no difference in the DNA quality following elution from the test strip. However, degradation was noted in saliva samples and some semen samples by STR analysis. Scientists are encouraged to consider processed test strips for DNA profiling to preserve evidence.
免疫层析试纸条在法医鉴定中用于推定识别血液、精液和唾液等感兴趣的体液的应用日益增加。通常，法医样本数量较少。在保存有限样本的实践中，若能从这些测试膜上回收沉积的遗传物质将是理想的。本研究旨在确定能否从精液和唾液试纸条中提取DNA，试纸条的哪一部分最适合使用，并评估回收的DNA质量。将精液和唾液样本分别滴加在SERATEC PSA半定量和淀粉酶测试条上并进行分析。然后从试剂盒中取出测试膜，采用DNA提取方法（法医通用GEM试剂盒、法医精子GEM试剂盒、QIAamp DNA微量提取试剂盒、Monarch核酸纯化试剂盒和有机提取法）进行提取。通过qPCR和STR分析评估质量。精液DNA最好使用Monarch核酸纯化试剂盒提取，而唾液DNA最好使用法医GEM试剂盒或QIAamp试剂盒提取。在样本加样垫和测试条的采集之间未观察到显著差异，因此鼓励使用整个试纸条。精液和唾液DNA在1:1000稀释时可定量。通过qPCR进行的DNA质量分析表明，从试纸条洗脱后的DNA质量没有差异。然而，通过STR分析发现唾液样本和一些精液样本存在降解现象。鼓励科学家考虑使用处理过的试纸条进行DNA分析以保存证据。
