尿液中DNA的提取与检验

尿液中DNA的STR分型检验有一定的应用价值:国外文献报道过应用于运动员兴奋剂控制^[1]中可疑尿检样品的个体识别,国内则偶有案发现场提取到尿液、尿冰、尿斑并成功进行个体识别的案例报道。与血液、精斑、唾液等检材相比,尿液STR分型的检出率较低,主要是与尿液中的成份有关。本文重点分析人类尿液成分,分类总结目前可用于提取尿液中DNA的多种方法,分析可能影响尿液STR分型检验结果的因素。     

环氧乙烷消杀DNA污染效果初探

目的初探环氧乙烷消杀DNA污染的效果。方法收集98例分别含有唾液、皮屑、汗斑、毛发、血斑、肋软骨的法医物证样本,分两组进行环氧乙烷灭菌6h和8h,提取DNA后扩增,使用3130XL或3500XL测序仪检测进行STR分型。结果 EO 6h组44例样本中有2例口腔拭子检出阳性结果,EO 8h组54例样本中有1例毛发检出阳性结果,阳性样本STR图谱表明仅有少量DNA残留,其余生物样本未检测到STR图谱。结论环氧乙烷能有效消杀DNA污染,可适用于DNA检验耗材的灭菌。     

A Simple and Efficient Method of Extracting DNA from Aged Bones and Teeth

DNA is often difficult to extract from old bones and teeth due to low levels of DNA and high levels of degradation. This study established a simple yet efficient method for extracting DNA from 20 aged bones and teeth (approximately 60 years old). Based on the concentration and STR typing results, the new method of DNA extraction (OM) developed in this study was compared with the PrepFiler? BTA Forensic DNA Extraction Kit (BM). The total amount of DNA extracted using the OM method was not significantly different from that extracted using the commercial kit (p > 0.05). However, the number of STR loci detected was significantly higher in the samples processed using the OM method than using the BM method (p < 0.05). This study aimed to establish a DNA extraction method for aged bones and teeth to improve the detection rate of STR typing and reduce costs compared to the BM technique.     

Texas Population Substructure and Its Impact on Estimating the Rarity of Y STR Haplotypes from DNA Evidence*

Abstract: Three sampled populations of unrelated males—African American, Caucasian, and Hispanic, all from Texas—were typed for 16 Y short tandem repeat (STR) markers using the AmpFlSTR^® Yfiler^TM kit. These samples also were typed previously for the 13 core CODIS autosomal STR loci. Most of the 16 marker haplotypes (2478 out of 2551 distinct haplotypes) were observed only once in the data sets. Haplotype diversities were 99.88%, 99.89%, and 99.87% for the African American, Caucasian, and Hispanic sample populations, respectively. F_ST values were very small when a haplotype comprised 10–16 markers. This suggests that inclusion of substructure correction is not required. However, haplotypes consisting of fewer loci may require the inclusion of F_ST corrections. The testing of independence of autosomal and Y STRs supports the proposition that the frequencies of autosomal and Y STR profiles can be combined using the product rule.     

Y—STR基因座分型缺失分析

目的分析Y—STR基因座等位基因分型缺失数据,为法医学提供应用参考。方法收集浙江汉族4477名无关男性个体血样,自动工作站磁珠法提取DNA,Y—filer^TM试剂盒进行复合扩增,Gene Mapper IDv3．2分析软件分析Y-STR数据,统计出现基因分型缺失的概率。结果在4477名无关个体的Y—STR数据中,有来自23种单倍型的26个样本Y-STR分型各有1个短片段基因座的基因分型缺失,而其它长片段基因座的分型均完全正常。基因分型缺失的发生频率为0．518％。结论Y-STR基因座分型缺失具有一定的发生率,在日常检案中应注意防止误判。     

微量口腔脱落细胞检材的DNA检验

目的寻求提高微量口腔脱落细胞检材的DNA检验成功率的简便有效的提取方法。方法对不同载体上的100份微量口腔脱落细胞检材采用小体积Chelex-100法提取DNA,在ABI7500型荧光定量PCR仪上进行定量,同时用IdentifilerTM复合扩增系统扩增,在ABI3130遗传分析仪上进行STR分型。结果从25根饮料吸管上提取的DNA量在0.72～116.7.8ng,16个水杯杯缘提取的DNA量在2.15-142.5ng,31个饮料瓶(罐)口提取的DNA量在1～34.65ng,10根筷子上提取的DNA量在3.35～26.6ng,12个果核中提取的DNA量在0.294～21.4ng,6份吃剩的骨头中提取的DNA量在0.88～5.88ng。100份检材性别及9个以上STR位点分型成功率平均为59.38%。除了使用者的个人原因外,检材的提取送检方式、检材的质地、饮料的性质对提取的DNA量有显著影响,是否加蛋白酶K对提取的DNA量无显著影响。结论采用小体积Chelex-100法可对60%左右的微量口腔脱落细胞检材提取DNA进行STR分型。     

北京汉族21个STR基因座的群体遗传学调查与法医应用评价

目的调查459例北京汉族无关个体21个常染色体非CODIS的STR基因座遗传多态性并评价其应用价值。方法用AGCU21＋1荧光标记复合扩增系统对459例无关个体的21个STR基因座（D6S474、D12SATA63、D22S1045、D10S1248、D1S1677、D11S4463、D1S1627、D3S4529、D2S441、D6S1017、D4S2408、D19S433、D17S1301、D1GATA113、D18S853、D20S482、D14S1434、D9S1122、D2S1776、D10S1435、D5S2500）进行检验。得到STR分型后,用相关软件进行统计分析并计算法医学应用参数。结果获得21个STR基因座的频率分布;相关参数为：H值从0.5894-0.8038,PD值从0.7898-0.9265,PE3值从0.3618-0.6029,PE2值从0.2031-0.4256,PIC值从0.5638到0.7640。结论联合应用Identifiler系统和AGCU21＋1系统,有利于亲子关系的认定及对可疑突变的判断。     

亲权鉴定中常用STR基因座的基因组学和遗传学分析

美国联邦调查局建立的联合DNA索引系统即CODIS系统至今已有10年,该系统确定的13个STR基因座及近年来开发的PentaD、PentaE、D2S1338和D19S433基因座被全世界范围内的实验室广泛采用,在亲权鉴定和罪犯数据库建设等方面发挥了重要的作用。本文利用Web of Knowledge核心检索系统和Elsevier等全文数据库及网络资源,对近年来常用STR基因座的基因组学特征和遗传学特征进行了深入地分析,并对这些STR基因座在实践中的应用情况进行了综述。     

4个STR基因座在广东汉族人群的单倍型分布

调查DYS19、DYS390和DYS389Ⅰ/Ⅱ基因座在广东汉族群体的单倍型分布。PCR扩增后,用不连续PAGE电泳系统分型。在130名无关男性个体中,共检出81种不同的单倍型,其中52种只出现过1次。4个基因座单倍型的遗传多样性、个体识别率和非父排除率分别为0.9989,0.9824,0.9824,结果表明,4个STR基因座的单倍型检测在法医学个体识别和亲权鉴定方面有较高的应用价值。     

武汉汉族6个STR位点多态性研究

应用PCR及PAGE电泳技术对武汉汉族人群作DIS1656、D2S441、DHFRP2、D8S1132、D10S2325、DXS6804等STR位点进行遗传学多态性调查,结果DIS1656、D2S441、DHFRP2、D8S1132、D10S2325位点分别检出基因10,8,5,10,11个,分别检出基因型42、26、13、38、44个;DXS6804女性检出5个等位基因型,14个基因型,男性检出7个等位基因.经检验,6个STR基因座基因型分布均符合Hardy-Weinberg平衡,累积个人识别能力为0.99999987,累积非父排除率为0.9939.DIS1656等6个STR均属高杂合度,高鉴别能力的遗传标记系统,在法医学个人识别和亲子鉴定中有较高实用价值.