目的:模拟现场快速FOB检测筛选后的阳性结果试纸条,探索阳性FOB试纸条用于DNA检测的可行性以及DNA检测的最佳区域。为此类案件后续的DNA检测提供新的实验思路,为侦查提供方向和线索。方法:以模拟现场快速FOB检测的10份阳性FOB试纸条(6男4女)为研究对象,将试纸条分为3个不同区域(A加样区,B反应区,C检测线),选用Chelex-100法对不同分区样本进行DNA的提取,用VFP (AB公司)试剂盒进行PCR扩增,用AB公司的3500 xl进行电泳,并且选用GeneMapper ID-X 1.5软件进行STR分型。通过直接计数法统计不同区域STR分型的得分情况,并且通过非参数检验的方法Kruskal-Wallis检验进行组间数据分析。结果:10份阳性FOB试纸条(6男4女)的3个不同区域不同程度地检测出来了人体特异性STR分型,三个区域得分如下:A区域最高得分43分、最低得分12分、平均得分21.4分;B区域最高得分50分、最低得分46分、平均得分48.9分;C区域最高得分14分、最低得分1分、平均得分7.8分;通过Kruskal-Wallis检验进行组间比较,得到P值为Objective: To explore the feasibility of positive FOB test strip for DNA detection and the optimal region of DNA detection by simulating the positive test strip screened by on-site rapid FOB detection. It provides new experimental ideas for the subsequent DNA detection of such cases, and provides direction and clues for investigation. Methods: Ten positive FOB test strips (6 males and 4 females) simulated on-site rapid FOB detection were used as the research objects. The test strips were divided into three different regions (A sampling area, B reaction area, C detection line). Chelex-100 method was used to extract DNA from samples in different regions. PCR amplification was performed with VFP (AB) kit, electrophoresis was performed with 3500 xl of AB company, and STR typing was performed using GeneMapper ID-X 1.5 software. The scores of STR typing in different regions were counted by direct counting m
The AGCU X Plus STR system is a newly developed multiplex PCR kit that detects 32 X-chromosomal STR loci simultaneously.These are DXS6807,DXS9895,linkage group 1(DXS10148,DXS10135,DXS8378),DXS9902,DXS6795,DXS6810,DXS10159,DXS10162,DXS10164,DXS7132,linkage group 2(DXS10079,DXS10074,DXS10075),DXS981,DXS6800,DXS6803,DXS6809,DXS6789,DXS7424,DXS101,DXS7133,GATA172D05,GATA165B12,linkage group 3(DXS10103,HPRTB,DXS10101),GATA31E08 and linkage group 4(DXS8377,DXS10134,DXS7423).A major advantage of this kit is that it takes into account linkage between loci,in addition to detecting more X-STR loci.In order to evaluate the forensic application of 32 X-STR fl uorescence amplifi cation system,PCR settings,sensitivity,species specifi city,stability,DNA mixtures,concordance,stutter,sizing precision,and population genetics investigation were evaluated according to the Scientific Working Group on DNA Analysis Methods(SWGDAM)developmental validation guidelines.The study showed that the genotyping results of each locus were signifi cantly accurate when the DNA template was at least 62.5 pg.Complete profi les were obtained for the 1∶1 and 1∶3 combinations.A total of 209 unrelated individuals from Southern Chinese Han community,consisting of 84 females and 125 males,were selected for population studies,and 285 allele profi les were detected from 32 X-STR loci.The polymorphism information content(PIC)ranged from 0.2721 in DXS6800,to 0.9105 in DXS10135,with an average of 0.6798.DXS10135(PIC=0.9105)was the most polymorphic locus,with discrimination power(DP)of 0.9164 and 0.9871 for the male and female.The cumulative PD_(F),PD_(M),MEC_(trio) and MEC_(duo) valu es were all greater than 0.999999999.There were 78 different DXS10103-HPRTB-DXS10101 haplotypes among the 125 males,and the haplotype diversity was 0.9810.There was no signifi cant difference in the cumulative PD_(F),PD_(M),MEC_(trio) and MEC_(duo) values whether considering linkage or not.In summary,the new X-STR multiplex typing system is effective and reliable,which can be u
