Y-STR家系排查在盗窃案中的应用报道

Application Report on Y-STR Pedigree Screening in Theft Cases

摘要: 目的：通过剖析一起盗窃案中微量生物物证的分析和比对全过程，探讨Y-STR家系排查在盗窃案中的应用。方法：用磁珠法提取DNA，采用VeriFiler^TM Plus和SureID^® PathFinder Plus扩增试剂盒分别扩增常染色体和Y染色体STR，扩增产物通过毛细管电泳进行STR分型。结果：磁珠法提取DNA，142份检材检出54份，检出率为38.03%。Y-STR分型结果排查比中两个家系：非本地家系(1容差)、本地家系(2容差)，结合案情综合分析优先考虑2容差家系，最后通过常染色体成功锁定犯罪嫌疑人。结论：磁珠法在此类盗窃案中脱落细胞类生物检材中检出率较高。Y-STR家系排查在盗窃案中有效缩小侦察范围，常染色体精准识别。在实际运用Y-STR家系排查中不能只考虑常规的遗传规律，不能完全以容差大小作为规律，需结合案情综合分析，让Y-STR家系排查在盗窃案中发挥最大作用。

Abstract: Objective: To explore the application of Y-STR family investigation in a theft case by analyzing and comparing the whole process of trace biological evidence in a theft case. Methods: DNA was extracted by magnetic bead method. VeriFiler^TM Plus and SureID^® PathFinder Plus amplification kits were used to amplify autosomal and Y chromosome STR, respectively. The amplified products were subjected to STR typing by capillary electrophoresis. Results: DNA was extracted by magnetic bead method, and 54 of 142 samples were detected, with a detection rate of 38.03%. The results of Y-STR typing were compared with two families: non-local family (1 tolerance) and local family (2 tolerance). Combined with the comprehensive analysis of the case, the 2-tolerance family was given priority, and finally the criminal suspect was successfully locked by autosome. Conclusion: The detection rate of magnetic bead method in exfoliated cell biological samples in such theft cases is high. Y-STR family investigation can effectively narrow the scope of investigation in theft cases and accurately identify autosomes. In the practical application of Y-STR family investigation, we can not only consider the conventional genetic law, but also not completely take the tolerance size as the law. We need to combine the comprehensive analysis of the case, so that Y-STR family investigation can play the greatest role in the theft case.