图像分析技术在测定细胞DNA含量推断死亡时间中的若干问题

图像分析技术为法医学早期死亡时间推断提供了一种新的方法,但目前仍有许多局限,本文将重点讨论标本的取材及固定、涂片或切片的选择、细胞群聚和重叠的处理、参考细胞核及门槛问题,以及个体差异对图像分析的影响及相应的解决方法。     

用小电泳进行DNA指纹图分析探讨

用小凝胶板电泳进行DNA指纹图分析,电泳时间缩短1/2,所需试剂及器材节省1/3～1/2,DNA最小检出量为0.8μg,使本方法重复性和实用性更为突出,值得推广应用。     

HUMARA基因座差异甲基化的法医学意义

目的　探讨X连锁差异甲基化多态性基因座的法医学应用意义。方法　以STR基因座HUMARA为例 ,应用甲基化敏感性限制酶消化后PCR技术 ,复合分析该基因座的STR多态性和甲基化状态 ,调查并比较男、女检材的分型效果。结果　基因组DNA经HpaⅡ消化后 ,男性没有扩增产物 ,女性分型不受影响 ,男女混合检材得到女性的分型图谱。女性单克隆瘤细胞只能检出 1个等位基因。结论　差异甲基化的HUMARA基因座是混合斑分析、性别鉴定和组织克隆性判断的有用工具。     

13个STR基因座在亲子鉴定案例中的基因突变观察

目的 观察美国 CODIS系统的 13个 STR基因座在532例认定亲子关系的亲子鉴定案中的基因突变情况,探讨STR基因座突变率及突变类型。方法 经“Profiler Plus”及“Cofiler”试剂盒检测的587例亲子鉴定案,对其中有1～2个STR基因座不符合遗传规律者,增加HLA等血型基因和“PowerPlex16~(TM)”试剂盒检测。必要时,还增加Y-STR基因座检测和HLA等位基因测序。结果 认定亲子关系的532例,观察1052次减数分裂,发现17例亲子鉴定中的18次基因突变事件,其中16例1个STR基因座的基因发生突变,1例2个STR基因座的基因发生突变;突变的基因座包括D5S818、D3S1358、D16S539、CSFIPO、D21S11、D13S317、D7S820、vWA、D18S51和FGA,其中以FGA和D18S51基因座的突变率最高(0.29％);18次突变事件,其中来自父亲11次,来自母亲5次,无法确定2次。结论 用美国CODIS系统的STR基因座进行亲子鉴定,在有1～2个基因座不符合遗传规律时,要综合分析,并增加其它的遗传标记进行检测。     

用PCR—测序法对人类线粒体DNA多态区的研究

用PCR方法，对线粒体DNA多态区15997至三6401区域进行扩增，产物DNA经纯化处理局直接进行自动化序列测定，得到了准确的序列结果。将得到的中国人mtDNA多态区序列与国外已报道的相应序列进行对比，证实我们所测序列与白种人相应序列之间存在碱基差异。     

DNA指纹技术在强奸案和亲子鉴定中的应用

在同一张膜上测定了18例无关个体血样,并计算出α-珠蛋白-3'HVR探针DNA指纹图的相关机率为4.0×10~(-12),平均每条谱带的相关机率为0.21。用此探针检验的14起强奸案和6起亲子鉴定案均获得肯定的结论。     

自动荧光分析法检验陈旧骨骼和牙齿的vWA和LPL位点

为鉴定陈旧骨骼和牙齿的尸源 ,对DNA的提取方法进行了研究,并建立了vWA和LPL位点的自动荧光分析技术,该法简便、快速、有效、可对存放2、3、4、7年的陈旧骨骼和牙齿成功地进行检验,在检验中能直接确定样品的等位基因     

上海地区D1S80位点基因频率分布及其在亲子鉴定中的应用

目的：将D1S80位点的DNA多态性分析应用于亲子鉴定。方法;PCR、聚丙烯酰胺凝胶电泳及溴已锭染色。结果：获得D1S80位点的DNA多态性分布数据。结论：D1S80位点的PCR检测方法可成功地用于亲权纠纷案的鉴定。     

DNA Profiling Success Rates from Degraded Skeletal Remains in Guatemala

No data are available regarding the success of DNA Short Tandem Repeat (STR) profiling from degraded skeletal remains in Guatemala. Therefore, DNA profiling success rates relating to 2595 skeletons from eleven cases at the Forensic Anthropology Foundation of Guatemala (FAFG) are presented. The typical postmortem interval was 30 years. DNA was extracted from bone powder and amplified using Identifiler and Minifler. DNA profiling success rates differed between cases, ranging from 50.8% to 7.0%, the overall success rate for samples was 36.3%. The best DNA profiling success rates were obtained from femur (36.2%) and tooth (33.7%) samples. DNA profiles were significantly better from lower body bones than upper body bones (p = <0.0001). Bone samples from males gave significantly better profiles than samples from females (p = <0.0001). These results are believed to be related to bone density. The findings are important for designing forensic DNA sampling strategies in future victim recovery investigations.     

D5S818 Typing Discrepancy Between PowerPlex® Fusion and Other STR Kits Including GlobalFiler® Caused by a One‐base Deletion in 31 Nucleotides Upstream of the Repeat Region

Short tandem repeat (STR) typing is widely used in forensic investigation. When the same DNA sample is analyzed with different STR typing kits, a typing discrepancy is occasionally observed. In this study, we examined the cause of a typing discrepancy in a sample at D5S818 locus. This sample was designated as 10, 12 using Identifiler^®, Identifiler^® Plus, GlobalFiler^®, PowerPlex^® 16HS, and PowerPlex^® 18D, but as 9.3, 12 using PowerPlex^® Fusion. Sequencing results indicated that the shorter allele in the sample had a deletion (U31Tdel) at 31 nucleotides upstream of the repeat region (AGAT)₁₀. This deletion was located in the binding site of the published D5S818 forward primer in PowerPlex^® 16 and was only 9 and 11 nucleotides downstream of our estimated 5′ end position of D5S818 forward primer in GlobalFiler^® and PowerPlex^® 18D, respectively. We also examined the effect of primer length on the heterozygous peak balance in this sample.