列车内部不同客体上接触性DNA检验方法的比较

Comparison of Contact DNA Extraction Methods on Different Subjects Inside the Train

比较了用于高铁与地铁列车内影响列车运营安全及车厢内与犯罪相关的关键部件表面接触性DNA的不同检验方法之间的效果差异,为实际检案提供参考和借鉴。通过实验模拟,徒手接触十种高铁与地铁列车内不同部件,分别采用棉签擦拭法和脱落细胞黏取器提取各部件上潜在的接触性DNA,并比较了螯合离子交换树脂(Chelex-100法)和Chelex-100联合横膜式超滤管(Microcon-100法)提取和纯化DNA的短串联重复序列(STR)分型效果。高铁列车通用钥匙、高铁列车行李架边缘、高铁列车折叠桌旋转卡口上的接触性DNA使用脱落细胞黏取器效果较好,而该方法使用在高铁列车上紧急制动阀、高铁列车紧急开门按钮盖板、地铁列车屏蔽门紧急开门装置、地铁列车紧急开门装置上效果较差;Chelex-100联合Microcon-100法的等位基因总检出率(28.1%)优于Chelex-100法(23.4%)。棉签擦拭法和脱落细胞黏取器对于列车内接触性DNA的提取各具优势,Chelex联合Microcon法是一种简便有效地提高列车内部接触性DNA检验效果的方法。

The result difference between different testing methods of contact DNA on the surface of key components which affect the operation safety of the train and related to the crime in the carriage were compared,and it provided references for the forensic investigation of actual criminal cases.Contact was simulated with the bare hands on 10 different objects inside the high speed train and subway.The contact DNA on the surface of all the objects were collected by cotton swab and shedding cell viscosis,and DNA were extracted and purified by Chelex-100 joint Microcon-100 method,respectively.The effect of short tandem repeat(STR)typing was compared and evaluated.Compared to the emergency brake valve,the cover plate of electric multiple unit(EMU)train emergency door button,emergency door opening device of metro platform and contact DNA on the emergency door opening device of metro train,the shedding cell adhesive device is better than the common key of EMU train,edge of luggage rack and rotary bayonet of folding table of EMU.The detection rate of alleles(DRA)of Chelex-100 joint Microcon-100 method(28.1%)was better than that of Chelex-100 method(23.4%).Cotton swab method and shedding cell viscosis have their own advantages in collection of contact DNA inside the trains,The Chelex-100 joint Microcon-100 method can be used as a simple and effective method to improve the detection effect of contact DNA inside the trains.The result difference between different testing methods of contact DNA on the surface of key components which affect the operation safety of the train and related to the crime in the carriage were compared,and it provided references for the forensic investigation of actual criminal cases.Contact was simulated with the bare hands on 10 different objects inside the high speed train and subway.The contact DNA on the surface of all the objects were collected by cotton swab and shedding cell viscosis,and DNA were extracted and purified by Chelex-100(chelating ion-exchange resin)joint Microcon-100 method,respectively.The effect of short tandem repeat(STR)typing was compared and evaluated.Compared to the emergency brake valve,the cover plate of electric multiple unit(EMU)train emergency door button,emergency door opening device of metro platform and contact DNA on the emergency door opening device of metro train,the shedding cell adhesive device is better than the common key of EMU train,edge of luggage rack and rotary bayonet of folding table of EMU.The detection rate of alleles(DRA)of Chelex-100 joint Microcon-100 method(28.1%)was better than that of Chelex-100 method(23.4%).Cotton swab method and shedding cell viscosis have their own advantages in collection of contact DNA inside the trains,The Chelex-100 joint Microcon-100 method can be used as a simple and effective method to improve the detection effect of contact DNA inside the trains.