复合扩增mtDNA-HVI和Cyt b片段鉴定混合血痕种属

Preliminary Study on Species Identification for Mixed Blood Stain by Multiplex Amplifying mtDNA-HVI and Cyt b Fragments

目的探讨mtDNA-HVI和Cyt b片段复合扩增法鉴定人与动物混合血痕种属的应用价值。方法用chelex-100法从人、牛、猪、狗、兔、鱼、鸡和鼠血痕中提取DNA,复合扩增mtDNA-HVI片段和Cyt b片段,琼脂糖凝胶电泳检测。结果人类在mtDNA-HVI区和Cyt b区分别出现279bp和358bp各一条带,且279bp条带亮于358bp;动物均只有358bp一条带。人与7种动物血痕的检测灵敏度均为3.13ng。检测人与动物混合DNA,灵敏度仍为3.13ng,但358bp条带亮于279bp条带。结论当358bp带明显强于279bp带时,提示检材为人与动物的混合。

Objective To explore species identification for blood strain of human and animal mixed origin through multiplex amplifying mtDNA-HVI and Cyt b fragments. Methods DNA was extracted from blood stains of human , bovine, swine, canine , rabbit, fish, chicken and mouse origin by using the chelex-100 method. Subsequently, duplex PCR reaction was carried out with two sets of primers targeting at mtDNA-HVI and Cyt b fragment respectively, and the amplified products were detected by agarose gel electrophoresis. Results A 279 bp mtDNA-HVI fragment and a 358 bp Cyt b fragment were detected from the human DNA sample when its DNA content is 3.13ng or more, and the former was brighter than the latter. For the animal DNA sample, however, only the 358 bp fragment was observed. Both fragments were also observed from the mixed sample of human and animal DNA when there was 25ng animal DNA and 3.13ng or more human DNA, but the 358 bp fragment was much brighter. Conclusion It suggested that the sample was a mixture of human and animal when both 279 bp and 358 bp bands were observed and the latter was much brighter than the former.