动物DNA分析技术及其法医学应用

动物DNA分析是法医非人源DNA分析的重要内容,对提供侦查线索和审判依据具有特殊的法医学价值.法医动物DNA分析主要涉及家养动物和野生动物两大类别.本文以动物DNA分析在法庭科学中的应用为切入点,综述了动物个体识别、亲缘鉴定、物种鉴定等,动物DNA分析中的遗传标记、检测技术等,并提出法医动物DNA分析存在的问题以及未来...     

定量PCR技术在法医学中应用的研究

目的研究荧光定量PCR技术在法医学中的应用。方法应用Taqman技术对法医各种生物检材进行DNA定量。结果该定量PCR技术对各种法医生物检材进行了准确定量,并判断检材中是否存在抑制物,从而指导了后续STR的检验。结论定量PCR技术是法医DNA检验中一项不可缺少的辅助技术。     

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。     

全基因组扩增技术应用于法医学的进展

全基因组扩增(whole genome amplification,WGA)技术是一种对全部基因组序列进行非选择性扩增的技术。对微量模板DNA的检验,一直是法医物证学特别关注和急需解决的难题之一。近年来,对WGA技术的的研究发展日渐深入,研究成果有望应用于法医DNA检验中各类微量检材的检验。本文综述了WGA技术在法医物证学中的研究进展和应用前景,为法医物证工作者提供参考。     

用Y—染色体特异DNA探针鉴识微量干血痕性别的研究

法医鉴识干血痕性别,通常是用盐酸阿地平染色观察 Y—小体的方法。重组 DNA 技术的发展与应用,为法医物证检验开辟了新的领域。本文用 Y—染色体特异 DNA 探针鉴识干血痕性别的成功,为法医的血痕性别签定,提供了一种新的检验方法。     

法医蛋白质组学研究进展与展望

随着质谱仪灵敏度的提升、蛋白质序列数据库的完善以及数据分析方法的成熟,蛋白质组质谱技术发展迅速,为其在犯罪调查应用奠定了良好的技术基础。蛋白质序列含有关于基因型的信息,而且蛋白质的表达水平与表型相关。因此,当生物物证没有DNA或者DNA降解非常严重,DNA检验技术无法实施或检验结果不佳时,对蛋白质序列和表达水平的检验就具有了独特的应用价值,如在毛发法医个体识别、体液斑迹组织来源等方面,可作为DNA检验技术的有效补充手段。本文综述了法医蛋白质组学的主要技术方法、法庭科学应用研究的最新进展以及在案件实际应用转化仍需重点研究的问题。     

DNA分析及其在法庭科学中的证据作用

在DNA分析技术应用于法医物证检验之前,法医物证技术只能对血液、精液、血斑、精斑、毛发、唾液斑等人体组织做有限的几种红细胞血型、酶型、血清蛋白型的检验,对血型不同的嫌疑人做出排除的结论,而血型相同时却达不到确认作案人的要求。1985年英国Leister大学遗传学部的Jeffreys首先将DNA分析技术应用于法医物证检验,为法医物证检验提供了新的检验方     

法医DNA分析技术的现状与最新进展

本世纪法医学最引人注目的成就就是将DNA分析技术应用于法医的个人识别和亲子鉴定。1985年，Jeffreys[1]将DNA指纹技术用于检验案件，标志着法医分子遗传学这一新领域的创建。它的出现使法医学中许多难题得以解决，近两年来，世界上众多的分子遗传学家和法医学家不断将最新出现的各种DNA分析技术应用于法医学，使得法医DNA分析技术不断得以改进，各种方法的优缺点得以相互补充，极大提高了DNA检验水平。目前，这一技术正朝着做足、高识别能力、简便的方向发展。本文就日前DNA分析技术的种类、方法、优缺点等作以简公、归纳，着重介…     

用于DNA提取的磁性纳米技术

磁性纳米技术用于DNA提取具有许多优势,如提取纯化一步完成、DNA定量提取、DNA提取自动化等,在法医DNA检验领域具有广阔的开发前景。本文就其主要的优点和技术方法作一简要综述。     

当前法医DNA研究热点

自80年代后期DNA技术应用于法科学以来,国内外有许多实验室都在法医DNA技术的研究上投入大量精力,由最初的RFLP（DNA指纹技术）拓展到了VNTR·PCR、STR－PCR、MVR－PCR、线粒体DNA测序技术及其他PCR相关技术,并将这些技术应用于办案实践。法医DNA技术在近几年进入了一个平台期,没有大的突破性研究进展,但仍存在着一些有待探索的课题。王法医DNA质量保证体系t‘〕法医DNA质量保证体系属于软科学研究领域。由于DNA检验结论能够认定或否定嫌疑人,是破案的重要甚至唯一的证据,也因为DNA检验复杂、难度大。环节多,…     

Validation of a multiplex PCR assay for the forensic identification of Indian crocodiles

A dependable and efficient wildlife species identification system is essential for swift dispensation of the justice linking wildlife crimes. Development of molecular techniques is befitting the need of the time. The forensic laboratories often receive highly ill-treated samples for identification purposes, and thus, validation of any novel methodology is necessary for forensic usage. We validate a novel multiplex polymerase chain reaction assay, developed at this laboratory for the forensic identification of three Indian crocodiles, Crocodylus palustris, Crocodylus porosus, and Gavialis gangeticus, following the guidelines of Scientific Working Group on DNA Analysis Methods. The multiplex PCR was tested for its specificity, reproducibility, sensitivity, and stability. This study also includes the samples treated with various chemical substances and exposed to various environmental regimes. The result of this validation study promises this technique to be an efficient identification tool for Indian crocodiles and therefore is recommended for forensic purposes.     

Resurrecting the Dodo: Positive control DNA for species identification

Positive controls are necessary standards for inclusion in forensic tests. When working as expected they demonstrate that methods have been applied correctly, and therefore results can be interpreted with confidence. However, the requirement for positive controls can also introduce problems. For species identification in wildlife DNA forensic testing, it is possible that the DNA sequence of the case sample will be a 100% match to the positive control. Whilst clear results for negative controls will indicate that cross-contamination is unlikely, it would be preferable to have a positive control that will not appear in casework. In addition, for many endangered species, obtaining positive control DNA for species-specific testing can be problematic. Here we present a simple method to use artificially generated positive control DNA from the extinct Dodo, Raphus cucullatus, for four species-identification tests run routinely in UK wildlife forensic casework.     

RNA在法医学领域中的应用及研究进展

随着分子生物学的发展,遗传学证据在法庭科学领域的应用也愈加广泛.DNA技术已经在个体识别和亲权鉴定中发挥着重要作用,而RNA技术正表现出越来越广泛的应用前景.本文就RNA在推断死亡时间、血痕形成时间、损伤形成时间、死亡原因及体液来源等领域的应用进行综述.     

A Pilot Study Comparing Postmortem and Antemortem CT for the Identification of Unknowns: Could a Forensic Pathologist Do It?

Forensic pathologists are commonly tasked with identifying human remains. Although DNA analysis remains the gold standard in identification, time and cost make it particularly prohibitive. Radiological examination, more specifically analog imaging, is more cost-effective and has been widely used in the medical examiner setting as a means of identification. In the United States, CT imaging is a fairly new imaging modality in the forensic setting, but in more recent years, offices are acquiring CT scans or collaborating with local hospitals to utilize the technology. To broaden the spectrum of potential identifying characteristics, we collected 20 cases with antemortem and postmortem CT images. The results were qualitatively assessed by a forensic pathologist and a nonmedically trained intern, and all cases were correctly identified. This study demonstrates that identification of human remains using visual comparison could be performed with ease by a forensic pathologist with limited CT experience.     

Application of species-specific polymerase chain reaction in the forensic identification of tiger species

Globally, tigers are considered to be endangered, and are listed on Appendix I of CITES. A simple test, using a species-specific primer pair, was developed to identify tiger meat, faeces and dried skin, and provide forensic evidence of illegal wildlife trade. The specific fragment of mitochondrial cytochrome b gene was also successfully amplified from raw DNA products extracted from single tiger hairs. This PCR-based approach opens a new avenue to forensic identification of less-than-optimal samples.     

Low-cost direct PCR for aged and processed wildlife sample analysis

Direct PCR has been used successfully in wildlife forensic DNA analysis from several types of biological samples using specialized, commercial direct PCR kits. This is attributed to the proprietary chemicals provided in the kits such as pre-PCR buffer and modified DNA polymerases. These reagents can be expensive, thereby limiting their widespread adoption in developing countries, where wildlife crimes are often encountered. We report on a study to evaluate the possibility of using low-cost direct PCR assay for degraded and processed wildlife sample analysis. Phire^® and Q5^® polymerases were used, due to their relatively low cost, for direct amplification of six aged and processed sample types (dried skin, 30-year old hair, muscle tissue, bone, trace blood mixed in vodka, and dried soft antler). The result indicated that Phire^® Hot Start II DNA polymerase and Q5^® DNA polymerase performed similarly to commercially available direct PCR kit. The low-cost amplification could efficiently identify species origin from all aged and processed samples. We observed a rate of more than 80% amplification success and high PCR product concentrations sufficient for further sequencing. The assay proved to be cost effective and robust; thus, we expect it to be adopted by wildlife forensic laboratories in developing countries.     

A Novel Application of a Cryosectioning Technique to Aid Scat Hair Microanalysis

Scat hair presents a diverse profile of hairs for morphological assessment that may find versatile applications in wildlife forensic investigations. Successful morphological assessment of scat hair microstructure, however, depends on a robust sectioning methodology. We assessed the feasibility and efficacy of a cryosectioning technique compared to that of a gold standard hand‐sectioning technique. Scat hairs were embedded in paraffin wax and hand‐sectioned, while cryopreserved scat hairs were sectioned with a cryostat. The results showed that cryosectioning preserved the pristine morphology of the scat hair and provided cross sections more amenable to high‐resolution imaging of hair internal microstructure than hand‐sectioning. The cryosectioning technique may find novel applications as a more reliable and robust technique to aid (i) scat hair internal microstructure analysis for cross‐referencing with species identification keys in wildlife forensic studies and (ii) downstream toxicological analysis in wildlife forensic studies as hair biochemistry is not altered during cryopreservation.     

allo-HSCT受者DNA嵌合状态研究进展及法医学意义

随着医疗新技术的迅速发展,造血干细胞移植在临床上的用途越来越广泛。移植后供者源细胞几乎存在于受者所有组织,必然对个人识别和亲权鉴定产生重要影响,应引起法医工作者的重视,避免因此而产生错误的司法鉴定结论。本文就近年来allo-HSCT受者不同组织DNA嵌合状态的研究进展及其对法医物证鉴定的影响作一综述,希望能对相关研究和实践提供参考。     

二代测序技术在Y染色体遗传标记分型中的法医学应用

法医遗传学领域常利用Y染色体的父系遗传特点,对非重组区遗传标记进行检测并用于亲缘关系鉴定、混合斑检测、家系排查以及种族推断等研究。目前毛细管电泳仍是应用最为广泛的检测技术,基于该技术的商业化检测试剂盒及数据分析处理系统十分成熟。随着生物信息量的增长,传统检测技术通量低的弊端逐渐显现,推动了法医DNA分型技术的革新。近年来,二代测序(next generation sequencing,NGS)技术发展迅速,其应用已被推广到包括法医遗传学在内的各领域,为Y染色体遗传标记的检测提供了新的技术手段。本文就NGS技术应用于法医学Y染色体遗传标记检测的研究现况和应用前景进行阐述,以期为后续司法实务提供新思路。     

DNA双股螺旋结构与迅猛发展的法庭科学——纪念人类DNA双股螺旋结构发现50周年

自1953年Watson和Crick发表DNA双股螺旋结构,它为人类生命科学,尤其是法庭科学的发展带来了历史性的变化。法庭科学从个体识别和亲子鉴定的排除到认定,经历了DNA指纹图、AMP-FLP及SNP的3个阶段。同时线粒体DNA的应用也在广泛开展。另外数据库的建设和完善成为法庭科学的发展方向。总之,DNA双股螺旋结构对法庭科学革命性变化起了决定性的作用。