陈旧颅骨的DNA检验

DNA Test of Aged Skull

陈旧颅骨DNA含量低且降解严重,一直是法医DNA检验的难点之一。本文介绍了一种改善陈旧颅骨DNA检验效果的方法,在几起陈旧颅骨案件DNA检验中,从取材部位的选择、脱钙液浓缩与回收、大体系提取纯化等方面对DNA提取进行优化,成功获得常染色体和Y染色体STR多态性检验结果。结果表明:颞骨岩部可作为陈旧颅骨检验优选的取材部位,与颅骨其他部位相比成功率较高;此外,在骨粉脱钙环节,利用Amicon Ultra-1510K离心超滤管可去除脱钙液中大量的水分和离子等小分子,从而将大分子DNA截留回收,有效降低了DNA损耗量;另外,陈旧颅骨DNA质量较差,提高骨粉使用量、增加提取纯化体系也能明显提升DNA回收量。本方法提高了陈旧颅骨的DNA回收量和质量,可为后续类似陈旧骨骼、牙齿DNA检验提供借鉴。

DNA test of aged skull is always a diffi cult problem in the fi eld of forensic science,as the skull contains little DNA,and the DNA degrades badly.Here,an improved method is introduced for DNA test of aged skulls.Taking the skulls in recent cases for example,the optimization was carried out from the selection of materials,concentration and recovery of demineralized solution,high volume extraction and purification of DNA,etc.Finally,the results of autosomal and Y chromosome STR polymorphism were obtained successfully.The results showed that petrosal part of temporal bone could be the preferred extraction site for the test of aged skulls,with a higher success rate compared with other parts of the skull;in addition,the use of Amicon Ultra-1510K centrifugal ultrafi ltration tubes could remove a large number of small molecules,such as water and ions in the decalcifi cation solution,so as to retain and recycle the large molecules of DNA,which effectively reduced the amount of DNA loss;furthermore,the quality of DNA was poor in aged skulls,so increasing the amount of bone powder used and increasing the extraction and purifi cation system could also signifi cantly improve the amount of DNA recovered.This method improves the quantity and quality of DNA recovered from aged skull,and can provide reference for the follow-up DNA test of similar aged bones and teeth.