线粒体单核苷酸多态性复合扩增体系在疑难检材中的法医学应用研究

Application of multiplex amplification of mitochondrial DNA single nucleotide polymorphism in the detection of complex forensic samples

目的应用线粒体单核苷酸多态性(SNPs)的复合PCR扩增体系应用于法医检验案件中的陈旧血痕、脱落细胞检材、腐败降解检材及骨组织等疑难检材,为解决法医学检验疑难检材的难题提供一种新的方法。方法用IdentifilerTM试剂盒进行目前使用的STR分型及已建立的18个线粒体SNPs(16个位于编码区和2个控制区)位点复合扩增毛细管电泳荧光检测体系,并行对照检验案件中的陈旧血痕、脱落细胞、腐败肌肉、软骨以及牙齿、骨等各种疑难检材。结果对于上述检材,STR与线粒体SNPs的检验成功率均达到80%以上,线粒体SNPs高于STR。对于高度腐败的肌肉及软骨、骨骼检材,线粒体SNPs的检验成功率明显高于STR。结论所建立的线粒体SNPs复合PCR扩增体系在疑难检材检验中具有良好的应用前景。

Objective To provide a new means for forensic examination of difficult samples including old blood stain, hair （containing hair shafts）, decomposed samples and old bone tissues using co-amplification of mitochondrial single nucleotide polymorphisms （SNPs）. Methods With IdentifilerTM kit, STR genotyping and 18 mtDNA SNPs （16 SNPs in the coding region and 2 in the control region） detection were carried out using multiple amplification with labeled fluorescence and capillary electrophoresis. The two methods were compared for their performance in forensic caseworks such as old blood stain, cast-off cells, degraded muscles, cartilages, teeth and old bones. Results The detection rates of STR and mtDNA SNPs were both beyond 80%, but the latter had a greater success rate. The success rates of mtDNA SNPs were significantly greater than those of STR in the examination of such samples as degraded muscles, cartilages, and old bones. Conclusion Multiplex amplification of mitochondrial DNA SNPs shows a bright prospect in the examination of difficult forensic samples.