Qiagen's Investigator™ Quantiplex Kit as a Predictor of STR Amplification Success from Low‐Yield DNA Samples,

Qiagen's Investigator? Quantiplex kit, a total human DNA quantitation kit, has a 200‐base pair internal control, fast cycling time, and scorpion molecules containing a covalently linked primer, probe, fluorophore, and quencher. The Investigator? Quantiplex kit was evaluated to investigate a value under which complete short tandem repeat (STR) failure was consistently obtained. Buccal swabs were extracted using the Qiagen QIAamp^® DNA Blood Mini Kit, quantified with the Investigator? Quantiplex kit using a tested half‐volume reaction, amplified with the ABI AmpFlSTR^® Identifiler kit, separated on the 3100Avant Genetic Analyzer, and data analyzed with GeneMapper^® ID v.3.2. While undetected samples were unlikely to produce sufficient data for statistical calculations or CODIS upload (2.00 alleles and 0.82 complete loci on average), data may be useful for exclusionary purposes. Thus, the Investigator? Quantiplex kit may be useful for predicting STR success. These findings are comparable with previously reported data from the Quantifiler? Human kit.     

05式警用转轮手枪弹壳接触DNA检验方法的比较

目的比较05式警用转轮手枪弹壳表面接触性DNA检验方法,为实际检验提供参考和借鉴。方法制备40例击发后手枪弹壳的模拟样本,分别用两步转移法提取弹壳表面不同部位检材,采用两种DNA提取法和两种扩增试剂盒对样本进行STR分型检验,比较评价检验结果。结果避开发射药残留区域采用两步转移法提取样本,有助于提高检出率;Chelex-100联合Microcon-100法提取模板DNA的产量最高可达1.18ng,高于Mini M48试剂盒法(0.91ng);MiniFilerTM试剂盒的等位基因检出率(23.61%)高于IdentifilerTM试剂盒(6.41%)。结论采用选择适当区域提取检材,采用Chelex-100联合Microcon-100法提取DNA,经MiniFilerTM试剂盒扩增,进行弹壳接触DNA分型的效果较好。     

3种甲醛固定组织DNA提取方法的比较

目的对不同方法提取甲醛固定组织中DNA的效果进行比较,寻找一种操作简便、经济实用、质量较高的DNA提取方法。方法取甲醛固定的心肌组织14份,分别以改良酚-氯仿法,改良Trizol法,试剂盒法提取DNA,进行紫外分光光度计测定OD260/OD280值后,经PCR扩增,琼脂糖凝胶电泳分析确定提取的DNA质量。结果改良酚-氯仿法,改良Trizol法,试剂盒法OD260/OD280比值分别为1.841 5±0.380 4、1.370 5±0.336 7、0.831 6±0.175 0。两两比较均有显著性差异(P<0.05)。3种不同方法提取DNA含量分别为0.943 8±0.530 1、0.707 5±0.423 6、0.342 8±0.182 5。PCR扩增后琼脂糖凝胶电泳显示以改良酚-氯仿法所提DNA的谱带清晰度好于其它两种方法。结论改良酚-氯仿法简便有效,所用试剂价格低廉,是一种经济实用的甲醛固定组织DNA提取方法。     

中国朝鲜族H19基因上游差异甲基化区SNP分布

目的调查中国朝鲜族群体中H19基因上游差异甲基化区(differentially methylated region,DMR)SNP及单倍型分布,为法医学应用及群体遗传学研究提供基础数据。方法收集中国朝鲜族101份无关个体血样和14份来自5个亲缘关系已知的两代家系血样,用PCR-循环测序、McrBC消化DNA后PCR方法检测H19基因上游DMR的SNP,并用亲源印记等位基因(parentally imprinted allele,PIA)分型法进行单倍型检测,再计算相关遗传学参数。结果在H19基因上游DMR 1174bp的目的基因扩增产物中,共检出13个SNP(rs10840167、rs2525883、rs12417375、rs4930101、rs2525882、rs2735970、rs2735971、rs11042170、rs2735972、rs10732516、rs2071094、rs2107425、rs4930098)和5种单倍型,有9个SNP属于高鉴别能力的遗传标记,其单倍型具有较高的个人识别率,单倍型平均基因多样性(GD)为0.714。应用McrBC酶消化基因组DNA的PIA分型法确定了家系子代样本的母源单倍型。结论 H19基因上游DMR在中国朝鲜族群体中具有很高的遗传多态性,母源单倍型的确定进一步提高了印记基因的法医学鉴定效能。     

DNA疫苗免疫佐剂的研究进展

简要阐述了细胞因子、共刺激分子、CpG DNA 和脂质体等 DNA 疫苗佐剂的来源、性质、免疫增强作用、作用机理和方式。认为以前的研究工作必然会使上述佐剂应用到 DNA疫苗的生产中。     

Recovery of Trace DNA on Clothing: A Comparison of Mini‐tape Lifting and Three Other Forensic Evidence Collection Techniques

Trace DNA is often found in forensic science investigations. Experience has shown that it is difficult to retrieve a DNA profile when trace DNA is collected from clothing. The aim of this study was to compare four different DNA collection techniques on six different types of clothing in order to determine the best trace DNA recovery method. The classical stain recovery technique using a wet cotton swab was tested against dry swabbing, scraping and a new method, referred to as the mini‐tape lifting technique. Physical contact was simulated with three different “perpetrators” on 18 machine‐washed garments. DNA was collected with the four different DNA recovery methods and subjected to standard PCR‐based DNA profiling. The comparison of STR results showed best results for the mini‐tape lifting and scraping methods independent of the type of clothing. The new mini‐tape lifting technique proved to be an easy and reliable DNA collection method for textiles.     

The Optimization of Electrophoresis on a Glass Microfluidic Chip and its Application in Forensic Science

Microfluidic chips offer significant speed, cost, and sensitivity advantages, but numerous parameters must be optimized to provide microchip electrophoresis detection. Experiments were conducted to study the factors, including sieving matrices (the concentration and type), surface modification, analysis temperature, and electric field strengths, which all impact the effectiveness of microchip electrophoresis detection of DNA samples. Our results showed that the best resolution for ssDNA was observed using 4.5% w/v (7 M urea) lab‐fabricated LPA gel, dynamic wall coating of the microchannel, electrophoresis temperatures between 55 and 60°C, and electrical fields between 350 and 450 V/cm on the microchip‐based capillary electrophoresis (μCE) system. One base‐pair resolution could be achieved in the 19‐cm‐length microchannel. Furthermore, both 9947A standard genomic DNA and DNA extracted from blood spots were demonstrated to be successfully separated with well‐resolved DNA peaks in 8 min. Therefore, the microchip electrophoresis system demonstrated good potential for rapid forensic DNA analysis.     

青海省喜马拉雅旱獭种群的遗传多态性分析

为了研究青藏高原喜马拉雅旱獭(Marmota himalayana)种群的遗传特征,以青海省同仁、乌兰、玉树县的喜马拉雅旱獭种群作为研究对象,利用13个微卫星DNA标记对其遗传变异情况及其种群结构进行了分析。通过有效等位基因数、基因多样性、Shannon指数、多态信息含量等参数对喜马拉雅旱獭不同种群内的遗传多态性进行了初步研究;采用除权配对法聚类分析绘制了旱獭的系统发育树,观察了各种群间亲缘关系。结果显示,青海省喜马拉雅旱獭种群均有高度的遗传多态性;它们可被分为两支:乌兰县和同仁县旱獭为一支,玉树县旱獭为另一支,这种种群特征与这3个县的地貌特点基本一致。研究结果为青藏高原喜马拉雅旱獭遗传资源的保护和利用提供了重要信息。     

提取CO Ⅰ基因片段鉴定嗜尸性蝇类

目的通过扩增蝇类COⅠ基因片段,结合形态学特征鉴定嗜尸性蝇类的种类。方法运用改良平衡酚—tris饱和酚法提取蝇类DNA,进行COⅠ序列扩增和测序,与数据库序列进行比对和分析。结果改良平衡酚—tris饱和酚提取DNA方法可获得有效的蝇类DNA,并可应用于COⅠ基因片段扩增,进而进行蝇类种类的鉴定。结论平衡酚—Tris饱和酚法提取的噬尸性蝇类虫体DNA作为模板,用于COⅠ序列扩增,测序后与数据库目的序列分析比对,可准确鉴定嗜尸性蝇类的种类;和传统的昆虫形态学特征鉴定方法比较,该体系更准确,应用范围更广。     

贵州汉族19个STR基因座多态性及法医学应用

目的调查19个常染色体STR基因座在贵州汉族人群中的等位基因分布,评估其在法医学中的应用价值。方法应用Goldeneye~(TM) DNA身份鉴定系统20A试剂盒,研究贵州520名汉族无关健康个体19个常染色体STR基因座多态性。用310型遗传分析仪进行毛细管电泳,Gene Mapper~ID v3.1进行基因分型。结果 19个常染色体STR基因座的杂合度为0.603 8~0.916 4,个体识别率为0.790 0~0.985 6,非父排除率为0.295 5~0.826 9,多态信息含量为0.553 5~0.908 9,累积个体识别率为1-1.230 0×10~(-22),累积非父排除率为0.999 999 99。贵州汉族和其他五个地域的汉族两两之间等位基因频率比较,仅贵州汉族与山东汉族、辽宁汉族、山西汉族之间存在基因频率差异具有统计学意义。结论 D19S433等19个常染色体STR基因座在贵州汉族人群中具有良好的遗传多态性,对群体遗传学和法医物证学研究有应用价值。