泥土中二氧化硅对硅珠法提取现场生物物证DNA的影响  

The effect of silica in soil on the extraction of biological evidence DNA at the crime scene using the silica bead method

作　　者：路陆 高泽华 吴天泉 郁丽燕 顾沈兵 贾东涛 Lu Lu;Gao Zehua;Wu Tianquan;Yu Liyan;Gu Shenbing;Jia Dongtao(Nantong Haimen District Public Security Bureau,Jiangsu Nantong 226100;Nantong Public Security Berean,Jiangsu Nantong 226007)

机构地区：[1]南通市海门区公安局,江苏南通226100 [2]南通市公安局,江苏南通226007

出　　处：《中国法医学杂志》2024年第1期112-114,共3页Chinese Journal of Forensic Medicine

摘　　要：目的研究泥土中二氧化硅对硅珠法提取现场生物物证DNA的影响。方法泥浆悬液和稀释血混合,制成混有灰尘、泥土的生物样本以模拟现场生物物证,分别用加热裂解和胍盐化学裂解的方式进行细胞裂解,硅珠法提取DNA后用Identifiler Plus试剂盒进行PCR扩增及毛细管电泳检测,并对电泳结果进行比较;用泥浆悬液代替硅珠提取稀释血DNA,反向验证泥土中二氧化硅对硅珠法提取现场生物物证DNA的影响。结果混有泥浆悬液的4μL、20μL稀释血加热裂解,提取扩增后得到完整STR分型,平均峰高1969.7±376.9 RFU、9706.7±349.8 RFU;混有泥浆悬液的4μL稀释血胍盐化学裂解,提取扩增后无法获得完整STR分型;混有泥浆悬液的20μL稀释血胍盐化学裂解,提取扩增后得到完整STR分型,平均峰高1899.8±801.3 RFU;泥浆悬液代替硅珠提取20μL稀释血得到完整STR分型。结论泥土中的二氧化硅在胍盐存在条件下会与DNA结合,导致硅珠法提取现场生物物证DNA的回收效率降低。Objective To study the effect of silica in soil on the extraction of biological evidence DNA at the crime scene using the silica bead method.Methods Mud suspension and diluted blood were mixed to prepare biological samples mixed with dust and soil,which is to simulate biological evidence at the crime scene.Cell lysis was performed using heating lysis and guanidine salt chemical lysis,respectively.DNA was extracted using the silica bead method,amplified by PCR using Identifiler Plus kit and detected by capillary electrophoresis.The electrophoresis results were compared.Using mud suspension instead of silica beads to extract diluted blood DNA to validate the effect of silica in soil on the extraction of biological evidence DNA at crime scene using silica beads method.Results The complete STR loci were obtained after the extraction and amplification of 4μL,20μL dilute blood mixed with mud and lysed with heating cracking,whoes average peak heights arel 969.7±376.9 RFU and 9706.7±349.8 RFU.For the 4μL dilute blood mixed with mud guanidine salt chemical lysis,it cannot obtain complete STR loci after extraction and amplification.20μL dilute blood mixed with mud guanidine salt was chemically cleaved and amplified to obtain complete STR loci with an average peak height of 1899.8+801.3 RFU.After extraction and amplification by mud suspension instead of silica beads to extract 20μL diluted blood DNA,complete STR loci were obtained.Conclusion Silicon dioxide in soil can bind to DNA in the presence of guanidine salts,leading to a decrease in the eficiency of recovering on-site biological evidence DNA using the silicon bead method.

关 键 词：法医物证学 DNA提取 土壤 二氧化硅 硅珠法 

分 类 号：D919.2[医药卫生—法医学]