PCR扩增体系的体积减少对DNA分析的影响

目的探讨PCR扩增体系的体积减少对DNA分析的影响。方法4份样品采用ProfilerPlus试剂盒,在同样条件下,对50μl、25μl、12.5μl、6.25μl四种体积的体系进行扩增,扩增产物分别经ABIPRISMTM310型基因分析仪、ABIPRISMTM377型测序仪、ABIPRISMTM3100型基因分析仪电泳,并经GeneScan3.1基因扫描软件和Genotyper2.5分析软件分析得到实验结果。结果小体积的扩增体系容易出现等位基因的丢失、额外等位基因的产生等现象。结论在检材情况较差时,应该慎用小体积的扩增体系。     

用Chelex100法及有机溶剂提取法联合提取DNA扩增STR基因座的比较研究

为了比较不同方法提取DNA扩增STR基因座的成功率 ,本文用Chelex10 0法及Chelex10 0法联合有机溶剂提取法分别提取性犯罪案件 6份血斑及 6份混合斑中精子DNA ,并用PE公司ProfilerPlus系统复合扩增 ,ABI 310型基因分型仪检测。结果表明 ,常规采用Chelex10 0法提取血斑及精斑等生物检材DNA作STR基因座检验失败或所检测的位点较少时 ,应对Chelex10 0法提取的DNA上清液再用有机溶剂提取法提取 ,可极大提高DNA检验成功率。采用本文建立的Chelex10 0法联合有机溶剂提取法 ,提高了PCR扩增阳性率 ,对实际检案很有帮助 ;在PCR扩增前应常规进行DNA定量检验 ,否则对于重要检材应进行梯度扩增。     

成都汉族、甘肃东乡族群体D10S1432和D10S1213 位点的遗传多态性分析

目的本研究的目的是了解人类基因组中D10S1432及D10S1213两个STR位点在成都汉族和甘肃东乡族群体中的遗传多态性分布及两个群体之间的关系。方法采用PCR、聚丙烯酰胺凝胶电泳及银染技术,共调查了209例样本。结果在D10S1432位点上观察到5个等位基因,15种基因型。在D10S1213位点上观察到9个等位基因,31种基因型。两位点的基因型频率在调查的两个群体中的分布符合Hardy-Weinberg平衡定律（P>0.05）。经统计,D10S1432在这两个群体中的杂合度为0.664和0.737,个人识别几率为0.827和0.820。D10S1213的杂合度为0.664和0.657,个人识别几率为0.836和0.882。结论结果表明,D10S1432和D10S1213两个位点在法医学个人识别和亲子鉴定中有较高应用价值。     

An updated validation of Promega's PowerPlex 16 System: high throughput databasing under reduced PCR volume conditions on Applied Biosystem's 96 capillary 3730xl DNA Analyzer

The PowerPlex 16 System from Promega Corporation allows single tube multiplex amplification of sixteen short tandem repeat (STR) loci including all 13 core combined DNA index system STRs. This report presents an updated validation of the PowerPlex 16 System on Applied Biosystem's 96 capillary 3730xl DNA Analyzer. The validation protocol developed in our laboratory allows for the analysis of 1536 loci (96 x 16) in c. 50 min. We have further optimized the assay by decreasing the reaction volume to one-quarter that recommended by the manufacturer thereby substantially reducing the total cost per sample without compromising reproducibility or specificity. This reduction in reaction volume has the ancillary benefit of dramatically increasing the sensitivity of the assay allowing for accurate analysis of lower quantities of DNA. Due to its substantially increased throughput capability, this extended validation of the PowerPlex 16 System should be useful in reducing the backlog of unanalyzed DNA samples currently facing public DNA forensic laboratories.     

XPG基因表达用于法医学年龄推断

目的探讨着色性干皮病G组(xeroderma pigmentosum group G,XPG)基因在不同年龄段健康汉族人群中的表达情况,分析XPG mRNA和蛋白表达量与年龄之间的相关性,以期为法医学年龄推断提供新的分子生物学指标。方法收集150名不同年龄段健康汉族人的外周血样,采用TRIzol法提取外周血单个核细胞(peripheral blood mononuclear cell,PBMC)总RNA,通过实时荧光定量PCR检测XPG mRNA在PBMC的相对表达量,酶联免疫吸附试验检测XPG蛋白在血浆中的表达量。结果 XPG mRNA及其蛋白表达量在≤18岁组与19~45岁组之间、≤18岁组与≥46岁组之间的差异均有统计学意义(P0.05),但19~45岁组与≥46岁组之间的差异无统计学意义(P0.05)。XPG mRNA和蛋白表达量均无性别差异(P0.05)。结论 XPG mRNA在PBMC的相对表达量在低龄段内随年龄增加而下降,其血浆中蛋白随年龄增加而升高;XPG基因有望成为法医学年龄推断的新型指标之一。     

Assessing the Utility of Soil DNA Extraction Kits for Increasing DNA Yields and Eliminating PCR Inhibitors from Buried Skeletal Remains

DNA identification of human remains is often necessary when decedents are skeletonized; however, poor DNA recovery and polymerase chain reaction (PCR) inhibition are frequently encountered, a situation exacerbated by burial. In this research, the utility of integrating soil DNA isolation kits into buried skeletal DNA analysis was evaluated and compared to a standard human DNA extraction kit and organic extraction. The soil kits successfully extracted skeletal DNA at quantities similar to standard methods, although the two kits tested, which differ mechanistically, were not equivalent. Further, the PCR inhibitors calcium and humic acid were effectively removed using the soil kits, whereas collagen was less so. Finally, concordant control region sequences were obtained from human skeletal remains using all four methods. Based on these comparisons, soil DNA isolation kits, which quickened the extraction process, proved to be a viable extraction technique for skeletal remains that resulted in positive identification of a decedent.     

ABO位点限制性扩增片段长度多态性的研究

建立了PCR扩增、限制性酶切、8％（T）、5％（C）聚丙烯酸胺凝胶垂直电泳和银染检测ABO位点的限制性片段长度多态性的方法体系。应用Amp-RFLP技术对185名中国人（哈尔滨）ABO位点的基因频率和基因型分布进行了调查和统计分析。ABO位点特异片段长度为140～200bp，基因频率为0．2000～0．5568。6种基因型频率为0．973～0．3135，杂合度0．5838，Dp值0．7146。经H－W平衡吻合度检测，完全符合群体遗传多态分布。通过对11个家庭33名相关个体的分析，证明完全符合孟德尔遗传定律。ABO基因型检验适用于法庭科学的个体识别和亲权鉴定。     

微量模板DNA扩增技术

综述了任意引物PCR和巢式PCR两种方法应用于微量模板DNA扩增的原理和应用优势。     

Y-STR在混合斑及亲缘鉴定案件中的应用

<正> 人类Y染色体除拟常染区(pseudoautosomal re-gion)外,大部分不与染色体发生重组,且序列结构特征能稳定地由父亲传递给儿子。对于父系家族的亲缘关系鉴定,Y-STR多态性具有实用价值。此外,利用PCR技术扩增Y-STR,可获得男女混合样品中男性成份的单倍型分型,而不受女性成份的干扰。在实际检案中,我们运用Y染色体10个STR基因座对遗留有混合精斑、血斑的强奸案件,凶杀案件及亲缘关系鉴定等多类案件进行了检验。     

浙江畲族人群9个STR基因座的遗传多态性

目的调查浙江畲族人群STR基因座的遗传多态性,为群体遗传学和法医学个人识别、亲子鉴定提供基础数据。方法采用AmpFlSTRProfilerPlus试剂盒(ABI公司),ABI310基因自动分析仪对浙江畲族120名无关个体血样的D3S1358、VWA、FGA、D8S1179、D21S11、D18S51、D5S818、D13S317和D7S820等9个STR基因座进行等位基因频率和基因型频率调查。结果获得浙江畲族人群9个STR基因座的基因频率分布资料,所有基因座基因型频率分布均符合Hardy—Weinberg平衡,计算得杂合度(H)0.655～0.960,个人识别率(DP)0.878～0.960,非父排除率(PE)0.363～0.677,多态信息总量(PIC)0.68～0.86。结论该9个STR基因座在浙江畲族人群中呈高度多态性,在法医学及人类遗传学研究中具有重要意义。