试验性法医DNA数据库的研究

A study of forensic DNA databases

目的 通过对大规模样本的 DNA分型 ,探讨 DNA数据库的建库指标 ;评估手动系统与自动系统 DNA分型的兼容性 ;探讨 DNA数据库计算机管理和需要立法解决的有关问题。方法 对 10 0 0份样本包括血液、血痕、唾液斑、精斑、混合斑、肌肉组织进行 D3S135 8、D9S1118、v WA、D5 S818、D16 S5 39、D8S1179、CSF1PO、D2 0 S16 1等 8个 STR基因座的 DNA分型。构建 8个 STR基因座的人类等位基因分型标准物 ;PCR扩增 8个 STR基因座。样本 PCR产物与等位基因分型标准物同步电泳 ,比较样本 PCR产物的电泳谱带对应分型标准物所处的位置 ,确定样本基因型。采用 Microsoft的 Access编写 DNA数据库计算机管理软件。结果 完成了对 10 0 0份样本 D3S135 8、D9S1118、v WA、D5 S818、D16 S5 39、D8S1179、CSF1PO、D2 0 S16 1等 8个 STR基因座的 DNA分型。构建了成都市试验性法医 DNA数据库。结论 明确了法医 DNA数据库建立的核心目的是为侦查提供犯罪嫌疑人的线索 ;所选择的 8个 STR基因座累积个人识别能力大于 0 .99999999,适合在成都群体中用于建立法医 DNA数据库。用于 DNA分型的手工电泳银染和自动激光荧光检测系统具有可重复性和兼容性 ,手工电泳银染更易向基层单位推广。设计的计算机管理软件允许现场生物检材

Objective The forensic DNA databases are very important for individual identification. In order to evaluate the genetic markers used for a forensic DNA databases and the compatibility between the manual DNA typing system and the automatic DNA typing system, a testing DNA database should be constructed. Also, constructing a testing DNA database can increase our understanding of the issue for forensic DNA databases. Methods A total of 1000 specimens, including samples of blood, blood stains, salvia stains, semen stains, mixture stains and muscle tissues, were collected from the public security bureau of Chengdu. The DNA of each specimen was extracted by Chelex method and analyzed using Amp FLP technique. A total of 8 STR loci, including D3S1358, D9S1118, vWA, D5S818, D16S539, D8S1179, CSF1PO and D20S161 were chosen and employed for DNA typing. Each STR locus was amplified by the polymerase chain reaction (PCR) and the PCR products were typed with the polyacryamide gel electrophoresis. Typing DNA was carried out by comparing with a human allele ladder. A total of 8 human allele ladders for D3S1358, D9S1118, vWA, D5S818, D16S539, D8S1179, CSF1PO and D20S161 were made in house. Managing software of the testing DNA database was designed using Microsoft Access. Results The results of DNA typing in 1000 specimens showed that the total discrimination power of 8 STR loci was over 0.99999999. Conclusion This study show that a forensic DNA database should be useful for search purpose. The total discrimination power over 0.99999999 imply that in principle there is no identical genotype at whole 8 STR loci between two persons from a population with 10000000 individuals. This means that 8 STR loci used in this study are suitable to construct forensic DNA databases in Chengdu of China. The result of DNA typing can be repeated and the data have compatibility between the manual DNA typing system and the automatic DNA typing system. The data search in our testing DNA database can be carried out using only some loci of the set of 8 STR markers. Also, the volume of our testing DNA databases could be enlarged easily. The implication from this study is that the legislation should not be negligent before establishing a forensic DNA database. This DNA database provides a model for establishing the forensic DNA databases in China.