215例枪支上接触DNA检材的检验分析

Analysis of 215 Touch DNA Samples Extracted from Guns

目的分析215例枪支上接触DNA提取、送检及检验结果,探讨枪支上接触DNA检出情况及可能影响检验结果的影响因素。方法收集自2013年以来受理的215例涉案枪支上接触DNA检材,按照提取部位、检出率、送检时间、检验方法进行分类并对数据进行统计分析。结果215例接触DNA成功检出35例,检出率为16.28%;枪支上不同部位接触检材的检出率无明显差异;硅膜法与改良硅珠法的检出率无明显差异;送检时间早的检材检出率高于送检时间晚的检材并具有统计学意义。结论枪支上接触DNA的检出率与提取部位、送检时间、检验方法等因素有关,日常类似检材应合理提取、及时送检并采取正确检验方法。

Objective To analyze the extraction,detection and tested results from 215 pieces of touch DNA samples obtained from case-involved guns so as to explore the detection rate and the potential infl uencing factors.Methods 215 pieces of touch DNA samples,collected from different positions of various guns involving with cases since 2013,were tested and statistically analyzed according to the extraction site,tested time,detection method and detection rate.Results Of the 215 pieces of DNA samples extracted from case-involved guns,35 ones were successfully detected of their STR profi les,resulting in a detection rate of 16.28%.No evident difference was found of the detection rate for the touch DNA samples to be extracted from various positions on the guns.There was no significant discrepancy of detection rate with either silicon membrane method or modified silicon-based one to extract the DNA.Certainly,a higher detection rate was shown from the earliertested samples,demonstrating signifi cant of statistics.Conclusions Detection rate of the touch DNA extracted from gun was somehow correlated with extraction site,tested time and detection method.Ordinarily,the samples of such kind should be extracted reasonably and timely tested with appropriate detection methods.