法医毒物领域生物基质标准物质的研究进展

生物基质标准物质是一类目标物与生物基质相结合的标准物质。生物基质标准物质与法医毒物领域所涉及的真实检材具有更高的一致性，其应用对提升检测结果的精确度具有积极作用。本文针对法医毒物领域常见的3种生物检材（血液、尿液和头发）对应的基质标准物质的研究进行综合阐述，重点介绍相应生物基质标准物质的制备工艺研究进展和部分现有产品及其参数评价，以期为法医毒物领域生物基质标准物质的研制及应用提供参考。     

法医DNA标准物质备选细胞STR等位基因片段长度的定值

目的 研究建立法医DNA标准物质备选细胞基因组STR基因座等位基因片段长度标准定值的方法.方法 利用有机法提取HPF和HSSM细胞基因组DNA并进行STR复合扩增,将产物进行电泳检测.利用Gene Mapper软件分析电泳结果,记录STR基因座等位基因的数值,并对目前我国公安系统应用较为广泛的DNATyperTM15、IdentifilerTM两种试剂盒扩增产物进行相应的DNA片段长度(bp)统计以及定值.结果 HPF为男性个体细胞,HSSM为女性个体细胞.HPF和HSSM细胞DNATyperTM15系统等位基因片段长度范围分别为126.26±0.05～367.53±0.20bp和125.33±0.07～370.08±0.17bp,IdentifilerTM系统等位基因片段长度范围分别为117.22±0.04～340.02±0.08bp和117.21±0.03～323.86±0.09bp.结论 对STR基因座等位基因片段长度进行标准定值,可为法医DNA标准物质提供有效的溯源途径.     

中国法医学会物证专业委员会法医DNA分析的若干建议

中国法医学会法医物证学专业委员会与国际法医遗传学会中文专委会于2006年10月在成都召开学术会议。我们的讨论强调有必要将国际法医遗传学会的信息及时传递到中国。因此,按照国际法医遗传学会的指南,我们推荐混合斑分析,法医DNA数据库及新遗传标记选择标准供同行参考。     

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。     

法医DNA实践中的伦理问题

法医DNA始终在国际法医物证检验领域中占据核心地位,技术应用早已广泛成熟。近年来,诸多学者开始关注法医DNA伦理学方面的研究,目前该研究还处于初步探索阶段。本文是在伦理学已有学术基础上,从DNA数据库建设和亲子鉴定两个方面对法医DNA伦理学思想应用现状进行了初步探讨,并且参考国内外文献资料对伦理学思想在法医DNA实践中的应用原则进行了阐述,目的在于衡量法医DNA工作是否达到伦理方面的要求,其实践意义将在DNA数据库建设和亲子鉴定中起到重要作用。     

应用自动化工作站提取常见生物样本DNA

目的建立使用自动化工作站提取法医案件生物样本DNA的方法。方法选用Biomek 3000自动化工作站,采用DNA IQTM系统及Chelex法对法医案件中常见生物样本进行DNA提取,荧光定量技术进行定量,PCR扩增16个STR基因座并与手工提取方法比较。结果与手工提取方法进行比较,选用自动化工作站结合使用DNAIQTM系统及Chelex法提取DNA可获得满意的STR检验结果。结论自动化工作站可用于法医案件中常见生物样本的DNA提取。     

国产法医DNA检验试剂耗材检测DNA标准品的准确性研究

目的利用法医DNA标准品对自主研发的法医DNA检验试剂耗材进行电泳检测准确性的实验考查。方法实验平台分为2个：平台1全部由美国AppliedBiosystems公司进口的3130xl遗传分析仪、16道电泳毛细管与甲酰胺、电泳缓冲液、凝胶构成;平台2由AppliedBiosystems公司进口的3130xl遗传分析仪、16道电泳毛细管与本实验室研发的甲酰胺、电泳缓冲液、凝胶构成。在实验平台上对allelicladder、内标等标准品以及阳性对照9947a的STR复合扩增产物进行电泳检测,利用GeneMapper软件对电泳结果进行分析。结果自主研发的法医DNA检验试剂耗材可与国外进口的3130xl遗传分析仪配套使用,构建的实验平台对法医DNA标准品的检测结果准确无误。结论自主研发的甲酰胺、电泳缓冲液、凝胶等法医DNA检验试剂耗材检测准确性达到了国外同类产品水平。     

法医DNA分析技术新方法与新产品的评估

法医DNA分析技术是目前世界各国司法警察部门在案件侦审过程中所依赖的重要技术手段之一。随着研究的不断深入,新的技术、方法、产品层出不穷,丰富了法医DNA技术检验体系,能够进行更多项目的检验。由于法庭科学是为侦查破案和法庭取证服务的,其鉴定结果可直接作为证据在案件审查中使用,因此,对法医DNA技术发展过程中所出现的新方法和新产品,世界各国尤其是发达国家在相关准入标准上要求严格,这有利于DNA检验技术获得良性发展,防止技术和产品使用的随意性,将技术的负面作用控制在最小范围内,让社会和公众信任。1评估规则的建立对法医DN…     

PowerPlex  16 HS系统在建立DNA数据库中的应用

免提取型法医DNA检测试剂盒是近年出现的新产品,具有成本低、速度快、操作简便等优点,在DNA数据库大样本量检验分析和检验标准化方面,优势明显。     

澳大利亚联邦警察局法医DNA实验室管理与质量控制简介

在国家留学基金委资助下，笔者于2011年作为国家公派访问学者赴澳大利亚联邦警察局（Austral—ianFederalPolice，简称AFP）法医及数据中心（Fo—rensicandDataCentre）交流学习。本文重点介绍最新的澳大利亚联邦警察局法医DNA实验室管理的基本情况及其目前质量控制（QualityControl，简称QC）的主要措施，结合我国的实际国情及法医DNA实验室管理及发展现状，探讨我国可以借鉴的法医DNA实验室管理制度、运行机制、质量管理等方面先进经验，供同行们借鉴和参考。     

基于重组质粒制备STR分型阳性参照物

目的基于重组质粒制备可用于校准法医STR分型的阳性参照物。方法以常用阳性参照物9948人类基因组DNA STR分型为依据,基于重组质粒构建包含CSF1PO、D7S820、TH01等40个常染色体位点,DYS391、DYS522、DYS385a/b等22个Y染色体位点以及性别判定基因座Amelogenin的STR分型阳性参照物。将重组质粒定量、稀释后等比例混合,分别应用于DNATyper~?19、DNATyper~?24、DNATyper~?Y、Amp F?STR~?Identifiler~?Plus以及Power Plex~?18D System五种扩增试剂盒。结果阳性参照物中各重组质粒浓度为0.01pg/μL~0.001pg/μL;应用于Amp F?STR~?Identifiler~?Plus PCR扩增试剂盒,基于重组质粒制备的阳性参照物与人类基因组DNA扩增检测结果差异较小;将此阳性参照物分别应用于不同公司、不同STR基因座的四种STR扩增试剂盒,电泳检测图谱显示各基因座基因型完整,分型正确,峰高相当,基因座间均衡性良好。结论基于重组质粒制备STR分型阳性参照物,是一种可以替代细胞系制备阳性参照物的方法,具有一定的参考价值。基于此方法制备的阳性参照物可适用于市面上常用的STR检验试剂盒,普适性较强,对法医DNA分型检测有一定的实用价值。     

法医学二代测序标准化进展与展望

二代测序技术可检测多种法医遗传标记获取海量序列信息,满足法医学实践中精准个体识别、复杂亲缘关系鉴定、特征刻画等应用需求。国内外已开展大量二代测序法医学应用科研工作,但由于缺乏行业标准,二代测序在我国公安实战中并未得到有效应用。目前,法医学二代测序的标准制定面临检测靶标特殊、测序技术流程和结果分析不统一等挑战。本文从核酸标准参考物、测序技术要求、序列多态STR等位基因命名规则等方面,梳理国外法医学二代测序标准化工作进展,并总结国内二代测序检测行业标准现状,希冀为我国法医学二代测序的标准建设提供思路和参考。     

Validation of cytochrome b sequence analysis as a method of species identification

One of the stages of dealing with biological material submitted to forensic laboratories is species identification. The aim of the present work was to validate and assess the possibility of applying sequence analysis of the region coding cytochrome b as a method of species identification in the field of forensic science. DNA originating from individuals from major phyla of vertebrates was isolated by the organic method from various specimens. Extracted DNA was subjected to PCR and direct cycle sequencing using a universal pair of primers. The validation process, performed according to TWGDAM recommendations, revealed that the technique is a very sensitive and reliable method of species identification allowing analysis of tiny amounts of material and also degraded material, and can be useful in the field of forensic genetics. The case example presented here, concerning the determination of species origin of biological evidence collected from fatal road accident, confirms that analysis can be carried out even when there is no reference sample, and the sequences obtained can be assessed through analysis of their similarity to sequences for cytochrome b present in DNA databases.     

Development and usage of a NIST standard reference material for real time PCR quantitation of human DNA

National Institute of Standards and Technology SRM 2372 human DNA quantitation standard has been produced to support the need for a human-specific DNA quantitation standard in forensic casework and calibration of new quantitative polymerase chain reaction (qPCR) assays. The conventional DNA concentration has been assigned with one of the U.S. National Reference UV/Visible Spectrophotometers, assuming an absorbance of 1.0 at 260 nm equals 50 ng/μL of double stranded DNA. In addition, an interlaboratory study has been conducted, to verify that the SRM 2372 materials perform well in currently used DNA quantitation assays by the forensic DNA community. Each unit of SRM 2372 consists of three well-characterized DNA extracts. Component A is a single-source human male material derived from blood. Component B is a multiple-source human female material derived from blood. Component C was purchased as a purified unsheared genomic human DNA (Sigma-Aldrich Co., St. Louis, MO) obtained as a lyophilized human genomic extract and has both male and female donors. SRM 2372 is intended to enable the comparison of DNA concentration measurements across time and place. Manufacturers can use SRM 2372 to validate the values assigned to their own reference materials. Individual forensic laboratories can use SRM 2372 to validate DNA quantitation methods and to verify the assigned concentration of in-house or commercial DNA calibration standards.     

中国法庭科学DNA数据库

本文综述了中国法庭科学DNA数据库的建立和发展过程、DNA数据库结构、内容、特点、作用以及存在的问题、发展方向、展望,目的是为如何进一步建设好具有中国特色的DNA数据库提供借鉴。     

Recommendations for consistent treatment of length variants in the human mitochondrial DNA control region

Human mitochondrial DNA (mtDNA) analysis is a valuable forensic tool, useful in cases where the amount of extracted DNA is low or highly degraded. Population databases are used to determine the relative rarity of a particular profile obtained in a forensic case. Rather than full DNA sequence information, sequence profiles are compared to a reference sequence, and the differences from the reference are recorded in forensic databases. A standard method is proposed for characterizing length variants, and examples are described using actual human control region mtDNA profiles. Consistency in alignment and nomenclature avoids inadvertently describing two sequences as different when in fact they are the same.     

Optimization and validation of a fully automated silica-coated magnetic beads purification technology in forensics

Automated procedures for forensic DNA analyses are essential not only for large-throughput sample preparation, but are also needed to avoid errors during routine sample preparation. The most critical stage in PCR-based forensic analysis is DNA isolation, which should yield as much highly purified DNA as possible. The extraction method used consists of pre-treatment of stains and samples, cell lysis using chaotropic reagents, binding of the DNA to silica-coated magnetic particles, followed by elution of the DNA. Our work focuses mainly on sample preparation, obtaining the maximum possible amount of biological material from forensic samples, and the following cell lysis, to create a simple standardized lysis protocol suitable for nearly all forensic material. After optimization and validation, the M-48 BioRobot((R)) workstation has been used for more than 20,000 routine lab samples. There has been no evidence of cross contamination. Resulting DNA from as small as three nuclear cells yield reliable complete STR amplification profiles. The DNA remains stable after 2 years of storage.     

The Relationship Between Deprivation and Forensic Opportunities with Stolen Vehicles

Abstract:  Collection and interpretation of forensic intelligence (primarily through DNA and fingerprint identifications) is an integral part of the investigation of criminal offenses ranging from burglary and vehicle crime to major crime. The forensic contribution depends not only on the successful recovery of material, but also the ability to identify potential offenders and apply this intelligence to solve the crime. This study examines burglary and vehicle crimes investigated by Northamptonshire Police (U.K.) by analyzing relationships between deprivation of a crime location and the recovery and identification of DNA and fingerprint material. The results show that, for stolen vehicles, although significantly more forensic material (both DNA and fingerprints) is recovered and identified in more deprived neighborhoods, this does not lead to a corresponding increase in solved cases. These findings are considered in relation to previous studies, which have advocated the prioritization of resources at crime scenes most likely to yield forensic material.     

RFLP band size standards: NIST standard reference material 2390

The procedural standard for DNA profiling developed by the U.S. advisory board on DNA quality assurance methods mandates annual confirmation of forensic DNA measurement systems against an appropriate reference material supplied by or traceable to the National Institute of Standards and Technology (NIST). NIST Standard Reference Material (SRM) 2390 is a suitable and appropriate standard for HaeIII restriction enzyme-based restriction fragment length polymorphism (RFLP) profiling systems. Originally issued in 1992, an among-laboratory SRM 2390 recertification study was initiated in 1997. Using data provided by the 20 state, local, or commercial forensic laboratory participants, quantitative band sizes values (expected mean values and associated bivariate tolerance intervals) are established for two different-source DNAs (female cell line K562 and healthy male "TAW") for genetic loci D1S7, D2S44, D4S139, D5S110, D1OS28, and D17S79. Methods for validating an RFLP measurement system, validating a control material or other secondary standard, and for tracing a particular set of RFLP measurements to NIST SRM 2390 are described in detail.     

生物检材中DNA损伤及修复研究进展

从犯罪现场遗留的生物斑迹中提取到的DNA样本可能因为长时间暴露于恶劣的环境中而遭受到各种类型的损伤,导致扩增失败不能获得分型结果。对这些受损伤的DNA样本进行修复并提高其检测成功率,是近年来法庭遗传学领域新的研究热点。本文通过对DNA损伤的原因和类型、DNA损伤修复机制、生物检材中DNA损伤修复研究和应用进行综述,希望能对相关研究和应用提供帮助。