骨皮质核DNA分析在法医学中的应用研究

Application of extraction and analysis of nuclear DNA from cortical bone in forensic medicine

目的:为探讨在白骨化案件的骨皮质中提取到一定质和量的可供核DNA分析的DNA模板,本文从受环境因素和生物因素影响较小的骨皮质中有效地提取到了核DNA,并成功地进行DNA分析,进行个人识别和亲子鉴定。方法:采集10根无关个体胫骨骨皮质,分别用有机法、Chelex-100法、有机法结合Chelex-100法、有机法结合磁珠纯化柱法4种方法提取骨皮质核DNA,用常规荧光标记复合STR基因分型法成功分析骨皮质核DNA,获得满意STR基因座分型。结果:有机法能提取到骨皮质核DNA,进行STR分型时部分样本图谱峰值不均衡;仅用Chelex-100法提取的核DNA得不到STR分型结果或出现较多的等位基因缺失;有机法结合Chelex-100法、有机法结合磁珠纯化柱法提取的核DNA均能成功进行STR分型,没有等位基因的缺失,其中有机法结合磁珠纯化柱法提取的核DNA检测成功率最高。结论:骨皮质中能提取到核DNA,可以成功地进行DNA分析。

Objective：To investigate the nuclear DNA extraction from cortical bones of which are less impacted by the environmental effect and biological effect of the dead and the analysis of the DNA typing will be successfully done to do individual identification or parentage testing. Methods： Genomic DNA was extracted from the cortical bone of shinbone of ten bones using the proteinase K/SDS-based organic method, the Chelex-100 method, a combined method, and the organic method combined with magnetic beads purification method. Target DNA was simultaneously amplified using a fluorescent multiplex ABI Identifier kit. The PCR products were analyzed on the ABI 3130 Genetic Analyzer. Results： The result showed that the STR genotype profiles obtained through the organic method were acceptable, despite preferential amplification at some loci. In contrast, no readable profiles could be determined when DNA was extracted by the Chelex-100 method, and there are a large number of allles missing. Our data suggest that cortical bone of shinbone can be used for nuclear DNA analysis, but the type of DNA isolation method used is critical. The traditional organic extraction method works reasonably well for cortical bone of shinbone DNA isolation, and combination of organic extraction and the Chelex-100 method or combination of organic extraction and magnetic beads purification works best. Conclusions： The feasibility of extraction and analysis of nuclear DNA from cortical bones of the dead and the STR genotype profiles were acceptable.