PCR-STR分型技术在尿样DNA分型中的应用

目的：对尿样的DNA分型进行研究。方法：10份尿样随机收集于无关个体,同时采集血液样本做DNA分型对照,用PCR－STD分型技术对尿样DNA进行FIBRA和D18S535基因座分型。结果：10份尿样10ml、1ml及0．2ml体积均获得准确的分型结果,且与同一个体的血样DNA分型结果完全相同;室温储存4天及4℃及4周的尿样均分型成功。结论：PCR－STR分型技术对尿样DNA分型是一种有效的方法,在尿样的个人识别中具有极高的实用价值。     

常染色体及X染色体STR用于同胞鉴定1例

本文通过PCR-STR分型技术,对1名认亲女性个体与4名已知同胞兄妹检测15个常染色体-STR基因座和14个X染色体-STR基因座,根据遗传规律分析及用判别函数进行判断,结果一致,排除认亲个体与4兄妹存在同胞关系。     

PCR法对HLA-DQ_α基因的分型及其在性犯罪鉴定中的应用

本文应用 PCR 法及 ASO 探针斑点杂交技术,对100例无关个体血液 DNA 及10例性犯罪案件混合斑中精子 DNA 进行了 HLA-DQα基因的扩增及其 DNA 分型。结果正常人0.1～0.3μgDNA 就能满足 DQα基因扩增的需要。在100例个体中可以观察到由4种等位基因组成的10种 DQα基因型。10例不同条件的混合斑中精子 DNA 经30～60次扩增后与 ASO 探针杂交均能准确地判定 DQα基因型。HLA-DQα是个体识别能力较强的遗传标志。本文为性犯罪中精子来源的个体识别提供了一个新方法,具有一定的实用价值。     

法医DNA分型的可重复性

为了了解国内法医DNA分型的可靠性，选择酪氨酸羟化酶基因第1内含子什＂mantyrosinehydroxylasegene,intron1）的短串联重复序列（STR）TH01基因座为遗传标记，在国内5个法医实验室进行了DNA分型的可重复性研究，报道如下。材料与方法一、样本制备和分送国内5个法医实验室参加本次研究工作，由华西医科大学法医学系作为协调单位，负责制备与分送盲测样本。每个法医实验室4份样本，2份为纯化DNA，2份为血痕。血液样品采自成都地区无血缘关系汉族个体，常规方法提取DNA；血痕样本由另外两名个体新鲜血液0．5ml滴于滤纸上制成，室温晾干…     

3种DNA提取法在污染严重混合斑分型中的应用比较

目的比较Chelex-100法、酚/氯仿法和二氧化硅膜法3种DNA提取法在污染严重混合斑分型中的应用效果。方法从日常案例中收集污染严重的混合斑25份,差异消化法分离精子后同时用Chelex-100法、酚/氯仿法和二氧化硅膜技术3种方法提取DNA,采用PCR-STR技术对D19S253、FGA和CSF1PO 3个基因座进行分型,Gel-Pro软件处理电泳图谱,SPSS软件分析比较不同方法之间的差异。结果采用Chelex-100法提取DNA,25份检材分型结果均未成功;采用酚/氯仿法,25份检材中10份分型成功,3份检材FGA和CSF1PO基因座可分型,4份检材CSF1PO基因座可分型;采二氧化硅膜纯化法,25份检材均成功分型;酚/氯仿法和二氧化硅膜法两种方法比较,结果存在显著性差异(P<0.05)。结论二氧化硅膜纯化技术可以有效去除PCR抑制物,提取的DNA扩增效果明显优于Chelex-100法和酚/氯仿法,具有较高的应用价值。     

车辆上脱落细胞STR检验

目的对汽车方向盘及变速杆把手上的皮肤脱落细胞进行STR检验研究。方法用EZ-tape采集车辆方向盘及变速杆上的脱落细胞,Chelex-100法与磁珠法结合提取DNA,延长保温时间。定量后调整PCR反应体系,适当增加PCR循环数,增加PCR产物量及延长进样时间进行电泳检测,使用GeneMapperIDV3.2软件进行STR分型。同时,对比使用多重置换扩增技术对提取的DNA进行全基因组扩增。结果对33份车辆方向盘和变速杆上脱落细胞的检测,其中19份检出全部基因座的基因分型结果,9份检出部分基因型,5份未检出DNA分型结果。而利用多重置换扩增技术未获得满意图谱。结论本研究建立的脱落细胞收集、DNA提取、PCR扩增及检测方法适合于车辆上脱落细胞的检验,其结果优于使用多重置换扩增技术获得的分型。     

车辆上脱落细胞STR检验

目的对汽车方向盘及变速杆把手上的皮肤脱落细胞进行STR检验研究。方法用EZ-tape采集车辆方向盘及变速杆上的脱落细胞,Chelex-100法与磁珠法结合提取DNA,延长保温时间。定量后调整PCR反应体系,适当增加PCR循环数,增加PCR产物量及延长进样时间进行电泳检测,使用GeneMapperIDV3.2软件进行STR分型。同时,对比使用多重置换扩增技术对提取的DNA进行全基因组扩增。结果对33份车辆方向盘和变速杆上脱落细胞的检测,其中19份检出全部基因座的基因分型结果,9份检出部分基因型,5份未检出DNA分型结果。而利用多重置换扩增技术未获得满意图谱。结论本研究建立的脱落细胞收集、DNA提取、PCR扩增及检测方法适合于车辆上脱落细胞的检验,其结果优于使用多重置换扩增技术获得的分型。     

尿蛋白酶抑制剂对尿样STR分型的影响

目的研究尿蛋白酶抑制剂(urinary trypsin inhibitor,UTI)对提高尿样STR分型成功率的作用。方法收集男女各5名健康志愿者中段尿,分装后分别添加不同质量浓度的UTI,-80℃保存,于8个不同的时间点进行DNA提取与Identifiler系统STR分型。比较15个STR基因座在不同组别尿样及来自同一个体对照血样的分型结果,计算不同组别尿样STR分型成功率。结果对照血样及保存期限为1 d的尿样15个STR基因座均分型成功,未经UTI处理的女性尿样3 d即发生基因座的丢失,9 d时检测不到任何基因座,而经UTI处理的女性尿样在9d之内均可以检测到15个STR基因座;未经UTI处理的男性尿样7d时检测不到任何基因座,而经UTI处理的男性尿样9d时STR基因座平均检出数约为9个。当尿液保存时间为30d时,经0.2、0.4和0.6μg/mL UTI处理的女性尿样的STR基因座检出率差异无统计学意义,平均为0.840 0±0.042 3,显著高于男性尿样的0.160 0±0.042 3。结论 UTI处理可显著提高尿样STR分型成功率,一定程度上延长尿样用于个体识别的保存期限。     

应用PCR-SSCP技术检测PGM1基因型

目的应用PCR-SSCP技术分型PGM1基因型.方法提取156份武汉地区汉族无关个体的血样DNA,分别扩增PGM1基因外显子4和外显子8的多态性靶DNA,用SSCP分析PCR产物,判断基因型.结果两种PCR产物均检出了两个等位基因、三种基因型,DP值分别为0.5620、0.4405.综合外显子4和8的PCR-SSCP结果,分出8种PGM 1基因型,DP值为0.731 8.应用本法对保存10年的陈旧血痕和精斑PGM1分型成功.结论用PCR-SSCP分型PGM1基因型在法医物证检验中具有实用价值.     

寡核苷酸芯片技术在HLA-A抗原基因分型中的应用研究

目的建立一种HLA-A位点的基因芯片分型方法,为HLA-A位点的基因分型提供一个较新的思路。方法利用基因芯片技术,根据HLA-A位点不同基因亚型的独特序列设计探针,制成分型芯片;待检测样品经PCR反应标记上荧光之后,与芯片进行杂交,根据杂交产生的荧光信号值分析确定样品HLA-A位点的基因亚型。将这一方法应用于100份标准DNA和200份无关个体的HLA-A位点基因分型并将部分样品进行测序。结果检测结果表明HLA-A基因分型芯片可准确分辨出A位点等位基因20大类,耗时2.5h。结论寡核苷酸芯片技术用于HLA-A基因分型,分辨率高、特异性强、重复性好、操作简便、结果直观,适合于法医学实践和临床应用。     

Genotyping for DQA1 and PM loci in urine using PCR-based amplification: effects of sample volume, storage temperature, preservatives, and aging on DNA extraction and typing.

Urine is often the sample of choice for drug screening in aviation/general forensic toxicology and in workplace drug testing. In some instances, the origin of the submitted samples may be challenged because of the medicolegal and socioeconomic consequences of a positive drug test. Methods for individualization of biological samples have reached a new boundary with the application of the polymerase chain reaction (PCR) in DNA profiling, but a successful characterization of the urine specimens depends on the quantity and quality of DNA present in the samples. Therefore, the present study investigated the influence of storage conditions, sample volume, concentration modes, extraction procedures, and chemical preservations on the quantity of DNA recovered, as well as the success rate of PCR-based genotyping for DQA1 and PM loci in urine. Urine specimens from male and female volunteers were divided and stored at various temperatures for up to 30 days. The results suggested that sample purification by dialfiltration, using 3000-100,000 molecular weight cut-off filters, did not enhance DNA recovery and typing rate as compared with simple centrifugation procedures. Extraction of urinary DNA by the organic method and by the resin method gave comparable typing results. Larger sample volume yielded a higher amount of DNA, but the typing rates were not affected for sample volumes between 1 and 5 ml. The quantifiable amounts of DNA present were found to be greater in female (14-200 ng/ml) than in male (4-60 ng/ml) samples and decreased with the elapsed time under both room temperature (RT) and frozen storage. Typing of the male samples also demonstrated that RT storage samples produced significantly higher success rates than that of frozen samples, while there was only marginal difference in the DNA typing rates among the conditions tested using female samples. Successful assignment of DQA1 + PM genotype was achieved for all samples of fresh urine, independent of gender, starting sample volume, or concentration method. Preservation by 0.25% sodium azide was acceptable for sample storage at 4 degrees C during a period of 30 days. For longer storage duration, freezing at -70 degrees C may be more appropriate. Thus, the applicability of the DQA1 + PM typing was clearly demonstrated for individualization of urine samples.     

两组引物对无毛囊毛根的PCR-STR分型

目的了解无毛囊毛根的短扩增子引物和通用引物PCR-STR分型在法医实践中应用的可行性。方法应用5对Bulter设计的短扩增子引物D8S1179、D21S11、THO1、D16S539和VWA与其对应的STR通用引物,利用非变性PAGE,对无毛囊毛根进行PCR-STR分型的对比研究。结果短扩增子引物与通用引物对无毛囊毛根分型的正确率:D8S1179为11.4%和17.1%、D21S11为3.7%和5.9%、vWA为22.2%和33.3%、THO1为9.3%和5.6%、D16S539为0和9.2%。毛根的短扩增子引物和通用引物部分STR分型出现了干扰结果的Ladder-like背景条带。结论在对无毛囊毛根检材进行通用引物和短扩增子引物PCR-STR分型时,五个STR位点分型检测的成功率有限,还需注意Ladder-like条带的干扰。     

D3S1754、D18S535基因座在中国北方汉族的多态性分析

目的 了解D3S1754、D18S535基因座多态性在中国北方人群中的分布特点及其应用价值。方法 使用PCR、聚丙烯酰胺垂直板电泳及银染的方法。结果D3S1754基因座检出9个等位基因（n=184）,D185535基因座检出8个等位基因（n=201）,两个位点的等位基因频率在群体中的分布符合Hardy-Weinberg平衡（P>0.05）,它们的杂合率（He）分别为0.706和0.807,个人识别机率（DP）分别是0.859和0.934,非父排除率（EPP）分别为0.464和0.629。结论 D3S1754、D18S535两个遗传标记的个人识别率高、非父排除能力较强且能稳定遗传,具有较高的应用价值。     

氨基比林血痕预试验处理血痕后样本的DNA定量

目的：探讨氨基比林血痕预试验处理血痕后样本DNA含量的变化及对STR分型检测的影响。方法10名健康无关个体EDTA抗凝血液制成滤纸血痕,氨基比林血痕预试验检测,按试验后血样干燥保存时间分30 min、1 h、3 h、6 h、12 h、24 h共6个实验组,并采用磁珠法、QIAcube DNA纯化法、Chelex-100法三种方法提取样本DNA,应用荧光定量PCR检测样本DNA含量,PCR-STR荧光技术进行STR分型。结果提取方法相同时,氨基比林血痕预试验后血样随干燥保存时间的延长,样本DNA含量呈逐渐降低的趋势。保存时间相同时,不同DNA提取方法间,样本DNA含量差异也有统计学意义。90.56%样本均可获得16个STR基因座明确分型。结论氨基比林血痕预试验对血痕样本DNA有损伤,24 h内多可获有效STR分型。磁珠法提取样本DNA进行STR分型,效果最好。     

Evaluation and usefulness of reverse dot blot DNA-PolyMarker typing in forensic case work

Experiments were performed to evaluate the Amplitype PolyMarker DNA typing system for application to forensic casework. DNA extraction using chelex was compared with phenol-chloroform extraction for various biological materials including postmortem blood, blood samples used for alcohol quantification, fresh urine, envelopes and cigarette butts. Different amounts of genomic DNA were amplified to test the sensitivity of the Amplitype PM. Mixed samples of two different bloods were typed to determine the dilution at which mixtures could be detected. Different storage conditions were evaluated using urine samples. Postmortem blood samples were typed during 4 months to determine the effects of natural degradation. A population sample of 105 unrelated individuals from South-West Switzerland was analyzed and the genotype frequencies were compared with those reported by others. Finally, practical usefulness of the Amplitype PM system is illustrated by analysing casework samples. The results of this validation proved the great usefulness and sensitivity of the Amplitype PM system using the appropriate extraction and typing method. However, mixed samples had to be interpreted with caution owing to the possibility of non-specific alleles with stored material such as urine and postmortem blood.     

全基因组扩增在微量检材DNA分型中的应用

目的探索全基因组扩增技术对微量检材DNA分型的有效性。方法通过显微操作制备含1~20个细胞的模拟微量检材样本,在常规PCR-STR分型前加入全基因组扩增步骤,从等位基因不平衡、等位基因丢失、基因座丢失、伪等位基因(包含stutter峰)等方面探究PEP和MDA两种全基因组扩增方法对微量检材DNA分型的有效性。结果 MDA扩增效率高于PEP,但等位基因丢失和伪等位基因严重;PEP方法的正确分型率高于MDA,但小片段DNA优势扩增现象较严重。结论 MDA方法并不适合目前以STR分型为主导的法庭科学,当微量检材样本的绝对量相当少时,可以考虑使用PEP方法来扩大样本量,以满足重复检验的要求,但可能面临大片段DNA扩增失败的风险。     

不同分型方法的STR分型差异

目的调查不同的STR分型系统之间分型的一致性。方法 10 0例不同个体的DNA样本分别用单位点聚丙烯酰胺凝胶银染法和PowerPlex16System试剂盒对 13个法医学常用STR位点进行基因分型 ,并比较两种不同分型系统间的分型结果。结果 1例样本在D8S1179位点出现了分型不一致的结果 :银染法的基因型为 12 / 14 ,而用PowerPlex16System试剂盒的分型则为 12 / 15。结论不同的STR分型系统可导致不同的基因分型     

9个miniSTR基因座在烧骨中的检测与分型

目的对300℃焚烧后成人股骨样本进行9个miniSTR（D20S1082、D6S474、D12ATA63、D9S1122、D2S1776、D1S1627、D3S4529、D2S441、Amelogenin）基因座的检测与分型。方法样本为8根经300℃焚烧后的成人股骨,用改良酚-氯仿法提取烧骨DNA,在Mastercylcerpro梯度PCR仪上对9个miniSTR基因座分别进行扩增,3130基因分型仪检测并收集电泳结果,GeneMarkerV2.2.0软件计算扩增产物片段相对大小以及进行样本基因型分型。结果8根烧骨样本均能够提取到DNA,浓度平均值为25ng/μL,D260/D280值在1.7~1.9之间。9个miniSTR基因座在样本中的检出率在78%~100%之间,分型图谱较清晰,个别样本出现额外带。结论本文9个miniSTR基因座分型检测的方法,可用于对烧骨捡材的DNA分型检验。     

Validation and implementation of the PowerPlex 16 BIO System STR multiplex for forensic casework

The PowerPlex 16 BIO multiplex short tandem repeat (STR) system contains the 13 CODIS loci (FGA, TPOX, D8S1179, vWA, D18S51, D21S11, TH01, D3S1358, CSF1PO, D16S539, D7S820, D13S317, and DS5S818), plus two pentanucleotide repeat loci (Penta D and Penta E) and the sex-identifying locus. Amelogenin. The PowerPlex 16 BIO System is optimized for use with the Hitachi FMBIO gel imaging systems. A consortium of seven independent laboratories collaborated to perform the studies defined by the FBI standards for performing a developmental validation, including the evaluation of sample concordance, percent stutter determination, nonprobative casework, precision, sensitivity, mixture determination, effect of substrates, the impact of environmental insults, and species specificity. All samples tested for concordance were consistent except for one sample from the Virginia Division of Forensic Science database that displayed discordance at D13S317, a locus whose primer sequence was altered. Stutter values were comparable to those of other STR multiplex systems, the precision was comparable to other multiplexes analyzed by gel electrophoresis, the DNA profiles were unchanged by the substrate upon which the blood samples were placed, and the nonprobative casework samples re-typed for the PowerPlex 16 BIO System were consistent with previous typing results. When greater than 0.125 ng of DNA was placed into the PowerPlex 16 BIO System amplification reaction, a full profile was generated by all laboratories. The mixture study results were comparable to those reported for other multiplex systems, the environmental study demonstrated a loss of larger molecular weight loci when samples were incubated at elevated temperatures for a prolonged period of time, and the only notable cross species hybridization was observed with primate DNA samples. This extensive validation work performed demonstrates that the PowerPlex 16 BIO System provides STR data of a quality comparable with other PowerPlex STR multiplex kits as well as other widely used STR multiplexes and is thus suitable for evidentiary casework analysis as well as database sample profiling.     

6个miniSTR基因座荧光标记复合扩增的遗传多态性

目的评价6个miniSTR基因座在DNA高度降解检材中的法医学应用价值,并调查广东汉族人群6个miniSTR基因座的遗传多态性。方法采用两个复合扩增PCR体系、四色荧光标记及毛细管电泳技术,对D1S1677,D2S441,D4S2364,D10S1248,D14S1434,D22S1045基因座进行基因型检测。结果6个miniSTR基因座均获得了清晰的基因型分型结果,扩增片段均小于120bp,分别检出7、7、5、8、8、7个等位基因和14、11、11、19、12、14种基因型,基因型分布均符合Hardy-Weinberg平衡。6个miniSTR基因座在广东汉族群体的个人识别率和非父排除率分别依次为0.863、0.895、0.792、0.894、0.814、0.904和0.392、0.360、0.353、0.568、0.378、0.513。10例IdentifilerTM试剂盒未能正确分型的高度降解DNA样本,采用6个miniSTR基因座复合扩增体系检测均提高了分型成功率结论6个miniSTR基因座荧光标记复合扩增体系在DNA高度降解检材的检测中具有较高的应用价值,并且在广东地区汉族群体中具有较好的遗传多态性。