载体法检验微量检材DNA

目的解决微量生物检材DNA检验难题。方法采用载体法对已知微量血样DNA进行检验，再与目前高灵敏度的Chelex-100提取的DNA检验的相应结果进行比较。结果载体法针对微量血样的DNA检验。不但能得到正确的STR分型结果．同时在检验灵敏度上比Chelex-100法高出2倍以上。结论载体法可提高微量生物栓材中DNA检出率，且操作简单，在法医检案工作中具有较高应用价值。     

小体系法提取微量DNA2例

1 案例 案例1 某年1月23日,一卖淫女(黄某,31岁)在出租房内被杀害.现场勘验人员用一团脱脂棉擦拭现场遗留的一个一次性塑料口杯边缘,对其进行DNA检验.由于脱脂棉太大,致使DNA浓度减小,多次提取未检出DNA.     

特殊处理尸块DNA检验1例

1 案例 1．1简要案情某女，42岁，某日在一较偏僻的养鸡场与某男发生争执后被对方用钝器击打致死。当晚，该男子将尸体放置于养鸡场的一大铁桶内，加入大量木炭并点火焚烧。次日将焚烧过后的残余尸体肢解，并分成几袋，然后将尸块装入一塑料桶内，洒上石灰粉，再用水泥浇筑。第3日，待水泥凝固后丢弃于附近河流中。     

手套印 DNA 检验在侦查破案中的应用

随着犯罪嫌疑人反侦查意识的提高,犯罪嫌疑人戴手套作案的情况越来越常见,手套印成为犯罪现场越来越多见的微量生物痕迹之一。如何从此类痕迹中获取犯罪嫌疑人的有效信息、为侦查破案提供有效线索具有重要意义。2012—2013 年,杭州市公安局DNA 实验室受理检验手套印拭子类检材共1 538 份,获得有效STR 分型146 份,有效检出率为9．5%。在入库的 146 个STR 分型中,有61 个STR 分型直接比中犯罪嫌疑人,比中率为48．6%,远高于数据库平均比中率。笔者结合本地应用情况,对犯罪现场的手套印从勘验、DNA 的转移提取及DNA 检验环节进行总结,供同行参考。     

存放19年精斑DNA检验成功1例

1案例 在一起性侵犯案件中．公安机关勘验现场后提取到受害人当时所穿军绿色短裤一条．后因证据不足释放嫌疑人。19年后,本实验室重新受理了此案件,对案发当时提取的短裤进行DNA检验。     

砖块上脱落细胞DNA分型检验

<正>1案例检验1.1简要案情郑某,男,2013年11月被发现死于家中床上。经现场勘查及法医检验,郑某系被人用砖块打击头面部致颅脑损伤死亡。提取现场两块沾有血迹的砖块要求进行DNA检验,以提供犯罪嫌疑人分型信息。1.2 DNA检验DNA提取根据嫌疑人可能的持砖方式,用棉签擦拭砖块1、砖块2后剪取棉纤维,加入裂解液500μL,56℃1h,95℃30min;采用硅珠法提取DNA,提     

微量生物物证DNA检验1例

本文应用STR分型技术,对他勒案件中同一勒绳不同部位上遗留的微量生物物-证进行检测,成功地确定了勒绳。现报道如下。1简要案情陈某,女,38岁。2006年3月14日被人勒死在家中。在现场垃圾篓中提取到怀疑为勒绳的手机充电器电源线1根。该电源线表面光滑,未见明显附着物,亦未检出人     

雨淋外衣上潜在血迹DNA检验1例

1 案例 某日,在某地发生一起杀人案件.嫌疑人余某作案后离开现场时正在下雨,雨水将其当时穿的衣服全部淋湿.10日后抓获余某,取其作案时穿的衣、裤进行检验.送检衣、裤均已晾干,颜色均为深蓝色,肉眼不能发现血迹,选择性地进行联苯胺试验,均未发现有阳性反应区.     

严重碳化脊柱DNA分型检验1例

<正>1案例资料1.1简要案情2010年某日某地发生一起车祸,车上人员被当场烧死。尸体仅存腰骶段脊柱,长58cm,椎弓完全碳化,椎体约1/3碳化,取1节附有部分椎间盘的椎体     

弃婴案中混合斑DNA分型拆分1例

<正>1案例1.1简要案情某日,在某公路旁发现1名遗弃男婴,发现时男婴已经窒息死亡。1.2 DNA提取及检验为获取弃婴的生母分型,在弃婴面部、颈部、胸部、腹部、腰部、臀部、左臂、右臂、左手、右手、左腿、右腿、左足、右足分别使用纯水浸润的棉签涂取采集脱落细胞,使用手术刀片切取脐带残端,同时抽取弃婴心血,制成FTA卡片[1]。     

Generating DNA profiles from immunochromatographic cards using LCN methodology

The aim of this research was to obtain DNA profiles from immunochromatographic test devices which have already yielded positive results with body fluids obtained from fourteen volunteers. Three different immunochromatographic cards for the identification of human blood and one for the identification of human saliva were used for this research. Each body fluid was detected using the appropriate immunochromatographic card. The used cards were kept at room temperature for various lengths of time. The membranes were removed at the end of the designated times and the entire strip was extracted using low copy number (LCN) extraction procedure. The extracted DNA was amplified using reduced amplification volume and higher PCR cycle numbers. Autosomal STR profiles were detected using AmpFℓSTR^® Identifiler™ PCR Amplification Kit from Applied Biosystems (AB). Additionally, DNA extracted from the male volunteers was amplified using the AB AmpFℓSTR^® Yfiler™ PCR Amplification Kit. Analysis of the amplified products was carried out by capillary electrophoresis injection on the AB 3130xl Genetic Analyzer. The generated DNA data was analyzed using the SoftGenetics GeneMarker^® HID Version 1.7 software.Autosomal and Y-STR DNA profiles were obtained from most of the cards which were stored at room temperature for up to three months. DNA profile was obtained from all four types of the immunochromatographic cards used in this study. These profiles were concordant with the profiles obtained from the donors’ reference samples.     

动物DNA分析在法庭科学中的应用

近年来,在法庭科学领域中,遇到越来越多的非人类DNA分型的问题,特别是来源于动物本身或者是动物的分泌物。作为证据,通过对犯罪现场非人类DNA的分型,不但可以知道在何地对何人或何物实施犯罪,而且,如果犯罪的实施方是动物,也可以知道其来自哪里。目前,在法医学领域,有关动物DNA分析方法的标准较少。根据国际法医遗传学会最新的研究成果,综述动物DNA在法庭科学中的应用现状和相关建议。     

miniSTR荧光检测体系的建立及法医学应用

目的 建立检测片段均小于150bp的miniSTR荧光检测体系,提高对微量降解检材DNA的检测效能. 方法 应用Primer Premier 5软件设计、FastPCR 6.0筛选引物,组合成用四色荧光标记引物的miniSTR复合扩增体系.优化PCR检测条件和引物浓度,在3100-Avant仪上用POP4胶进行电泳检测.分型结果用DNA标准品9947A和007进行验证,并通过检测新鲜血样、疑难微量检材评估该体系的法医学应用效能.结果 建立的miniSTR荧光检测体系（D12A TA 63、D2S1776、D1GA TA 113、D4S2408、D17S974、D20S482、D3S3053、Ame logenin、D6S474、D9S1122）中各基因座的检测片段均小于150bp,各等位基因扩增均衡性良好,无非特异性扩增产物,等位基因频率分布符合Hardy-Weinberg平衡,累积个体识别率为0.999999983,三联体累积非父排除率为0.996 8.能成功检测腐败肌肉组织、低拷贝数DNA检材以及在40％甲醛溶液中固定12d的人体组织. 结论 miniSTR荧光检测体系可独立应用于降解DNA样本的个体识别鉴定或补充应用于亲权鉴定,提高对微量、降解检材DNA的检测能力.     

拷贝数变异及其在法医学中的研究进展

近年来拷贝数变异的研究已逐渐延伸至各个领域,如复杂疾病病因探索、精准治疗以及遗传育种和进化等。拷贝数变异独有的遗传学特点使得人们逐渐相信其可以成为解决相关问题的生物学遗传标记。随着检测技术的发展,拷贝数变异在法医学方面的应用也将逐渐增多。本文就拷贝数变异概念与发展以及在法医学中的应用进行阐述,为今后拷贝数变异的实际应用提供新的思路。     

利用AutoMate Express~(TM)自动化法医DNA提取系统提取骨骼及牙齿DNA

目的探讨建立骨骼及牙齿DNA自动化提取的新方法。方法将33份骨骼及15份牙齿样本分别用冷冻研磨和手工处理两种方法研磨成粉,采用AutoMate ExpressTM自动化法医DNA提取系统提取DNA并定量。结果 AutoMate ExpressTM自动化法医DNA提取系统能够在3h左右完成骨骼、牙齿DNA的提取,两种方法处理的骨骼样本所得DNA质量浓度差异无统计学意义。冷冻研磨处理的骨骼和牙齿样本均获得了较好的STR分型结果,且牙齿样本所得DNA质量浓度高于手工提取所得。结论应用AutoMate ExpressTM自动化法医DNA提取系统是自动化提取骨骼、牙齿DNA的一种新方法,可应用于法医实际案件检验。     

低拷贝DNA模板检验方法探讨

目的探讨扩增及检测方法对低拷贝DNA模板分型检测灵敏度的影响。方法Control DNA 9947A按比例稀释,采用IdentifilerTM和DNATyper15TM试剂扩增,循环参数设置为28和28+6个循环,平行扩增3次,分别单独检测及3次合并检测,使用310及3130分析仪检测。结果28+6个循环的基因座检出率高于28个循环;等位基因不平衡及丢失与基因座没有特异性的关联,随着DNA模板量的减少,等位基因不平衡及丢失增多;将3次扩增产物混合后检测,等位基因不平衡及丢失情况减少,分型正确率增高。结论模板DNA分3次扩增后混合检测、循环数为28+6,可提高低拷贝模板基因座的检出率。     

微量DNA的短串联重复序列分型可行性

目的了解微量DNA分型的法医学应用的可行性。方法一系列浓度的DNA模板用PowerPlexTM16System试剂盒扩增,并用ABI377DNA测序仪进行短串联重复序列(STR)的分型。结果当模板量小于250pg时,部分位点发生了等位基因漏扩,并出现非特异带、杂合子扩增不平衡等干扰分型的杂峰。结论上述这些不正常的现象可能会导致分型错误。在对微量检材的DNA检验结果进行判型时一定要小心谨慎,全面考虑。     

Simplified low-copy-number DNA analysis by post-PCR purification

Frequently, evidentiary items contain an insufficient quantity of DNA to obtain complete or even partial DNA profiles using standard forensic gentotyping techniques. Such low-copy-number (LCN) samples are usually subjected to increased amplification cylces to obtain genetic data. In this study, a 28-cycle polymerase chain reaction (PCR) was used to evaluate various methods of post-PCR purification for their effects on the sensitivity of fluorophore-based allelic detection subsequent to capillary electrophoretic separation. The amplified product was purified using filtration, silica gel membrane, and enzyme mediated hydrolysis purification techniques and evaluated for their effect on fluorescent allelic signal intensity. A purification method was selected and its effect on fluorescent allelic signal intensity was compared with that of the unpurified PCR product. A method of post-PCR purification is described which increases the sensitivity of standard 28-cycle PCR such that profiles from LCN DNA templates (<100 pg DNA) can be obtained. Full DNA profiles were consistently obtained with as little as 20 pg template DNA without increased cycle number. In mock case type samples with dermal ridge fingerprints, genetic profiles were obtained by amplification with 28 cycles followed by post-PCR purification whereas no profiles were obtained without purification of the PCR product. Allele dropout, increased stutter, and sporadic contamination typical of LCN analysis were observed; however, no contamination was observed in negative amplification controls. Post-PCR purification of the PCR product can increase the sensitivity of capillary electrophoresis to such an extent that DNA profiles can be obtained from <100 pg of DNA using 28-cycle amplification.     

The application of ultraviolet irradiation to exogenous sources of DNA in plasticware and water for the amplification of low copy number DNA

Using high sensitivity forensic STR polymerase chain reaction (PCR) typing procedures, we have found low concentrations of DNA contamination in plasticware and water assumed to be sterile, which is not detected by standard DNA procedures. One technique commonly used to eliminate the presence of DNA is ultraviolet (UV) irradiation; we optimized such a protocol used in the treatment of water, tubes, plates, and tips for low copy number DNA (LCN) amplification. UV light from a Stratalinker((R)) 2400 was administered to 0.2, 1.5 mL tubes, and PCR plates contaminated with up to 500 pg of DNA. They were subsequently quantified with an ALU-based real-time PCR method using the Rotorgene 3000. Overall, there was a decrease in concentration of DNA recovered as the duration of treatment increased. Nonetheless, following 45 min of irradiating a PCR plate with 500 pg of DNA, nearly 6 pg were still detected. However, when the plate was raised within an inch of the UV source, less than 0.2 pg of DNA was detected. Additionally, lining the area around the samples with aluminum foil further reduced the amount of time necessary for irradiation, as only 30 min eliminated the presence DNA in the raised PCR plate. Similar experiments were conducted using tubes filled with a solution of DNA and water in equivalent concentrations for 50, 15, and 1.5 mL tubes with comparative results. It is plausible that the aluminum foil increased the amount of reflection in the area thereby enhancing penetration of UV rays through the walls of the plasticware. This protocol was tested for the possibility of inhibitors produced from irradiation of plastic tubes. As our protocols require less irradiation time than previous studies, PCR sensitivity was not affected. Moreover, the lifespan of the UV lamps was extended. Our findings demonstrate that this method is useful as an additional precautionary measure to prevent amplification of extraneous DNA from plasticware and water without compromising the sensitivity of LCN DNA amplifications.