Biological traces discovered at crime scenes hold significant significance in forensic investigations. In cases involving mixed body fluid stains, the evidentiary value of DNA profiles depends on the type of body fluid from which the DNA was obtained. Recently, coding region polymorphism analysis has proved to be a promising method for directly linking specific body fluids to their respective DNA contributors in mixtures, which may help to avoid "association fallacy" between separate DNA and RNA evidence. In this study, we present an update on previously reported coding region Single Nucleotide Polymorphisms (cSNPs) by exploring the potential application of coding region Insertion/Deletion polymorphisms (cInDels). Nine promising cInDels, selected from 70 mRNA markers based on stringent screening criteria, were integrated into an existing mRNA profiling assay. Subsequently, the body fluid specificity of our cInDel assay and the genotyping consistency between complementary DNA (cDNA) and genomic DNA (gDNA) were examined. Our study demonstrates that cInDels can function as important multifunctional genetic markers, as they provide not only the ability to confirm the presence of forensically relevant body fluids, but also the ability to associate/dissociate specific body fluids with particular donors.

在犯罪现场发现的生物痕迹对于法医调查具有重要意义。在涉及混合体液染色的情况下，DNA 图谱的证据价值取决于获得 DNA 的体液类型。最近，编码区多态性分析已被证明是一种很有前途的方法，可以将特定体液与其各自的DNA贡献者在混合物中直接联系起来，这可能有助于避免单独的DNA和RNA证据之间的“关联谬误”。在这项研究中，我们通过探索编码区插入/删除多态性（cInDels）的潜在应用，对先前报道的编码区单核苷酸多态性（cSNP）进行了更新。根据严格的筛选标准，从 70 个 mRNA 标记中选出了 9 个有前途的 cInDels，并将其整合到现有的 mRNA 分析测定中。随后，我们检查了 cInDel 测定的体液特异性以及互补 DNA (cDNA) 和基因组 DNA (gDNA) 之间的基因分型一致性。我们的研究表明，cInDels 可以作为重要的多功能遗传标记，因为它们不仅能够确认法医相关体液的存在，而且还具有将特定体液与特定供体关联/分离的能力。