生物质谱技术在法医遗传学中的应用展望

随着基质辅助激光解吸电离质谱 (MALDI MS)和电喷雾离子化质谱 (ESI MS)两种技术的迅速发展 ,生物质谱技术已经成为生命科学研究中的重要工具。由于直接检测分子的质量 ,质谱技术同其他方法相比更加准确。生物质谱技术在核酸序列分析中具有快速性、微量化、和高通量的特点。利用MALDI TOF MS技术可以分析降解检材的SNP遗传标记 ,这在法医学中将有着重要的意义。本文对生物质谱技术的原理、进展、面临的困难以及在法医遗传学中的应用前景作了评述     

人体生物性物质来源鉴定及法医学应用研究进展

犯罪现场中人体生物性物质来源鉴定在重现犯罪过程方面发挥了重要作用,寻找特异性遗传标记鉴定人体不同生物性物质来源是近年来法医学工作者研究的重点和难点。本文就目前研究较多的用于人体生物性物质来源鉴定的遗传标记进行综述,包括DNA甲基化、mRNA、microRNA、微生物菌群、蛋白质等。通过比较不同种类遗传标记鉴定人体生物性物质来源的原理和方法,发现人体不同生物性物质来源的鉴定都有其最适合的遗传标记种类,并且可以采用单一遗传标记或联合多种遗传标记进行检验。尽管目前各法医学实验室无统一的标准和方法鉴定人体生物性物质来源,但研究开发一系列成熟可靠的方法区分人体不同生物性物质,进而发挥其法庭证据作用,将是未来的发展方向。     

论专家辅助人意见——以刑事辩护为视角的分析

我国2012年新《刑事诉讼法》首次设立专家辅助人制度，对鉴定意见的质证提供了技术上的支持，对于刑事辩护来说意义重大。从证据法的角度看来，专家辅助人意见具有言词证据、意见证据、弹劾证据的多重属性，因此意见的内容应围绕鉴定意见中的专门性问题，并结合《刑事诉讼法》及相关司法解释对鉴定意见的审查判断规则来提出；而法庭对于鉴定意见的审查也应从准入资格与可靠性两方面进行，以免专家辅助人意见替代鉴定意见来主导审判。     

Exploring the recovery and detection of messenger RNA and DNA from enhanced fingermarks in blood

Often in the examination of bloodstained fingermarks discussion occurs around whether to prioritise the fingerprint evidence or focus on the biological evidence. Collecting a sample for genetic profiling may result in the loss of ridge detail that could have been used for fingerprint comparison. Fingermark enhancement and recovery methods along with sample collection methods could also compromise downstream genetic analysis. Previous forensic casework has highlighted circumstances where, after enhancement had been performed, it would have been extremely valuable to both identify the body fluid and generate a DNA profile from the same sample.We enhanced depletion series of fingermarks made in blood, using single treatments consisting of aqueous amido black, methanol-based amido black, acid yellow and leucocrystal violet, and exposure to long wave UV light. We then extracted the DNA and RNA for profiling, to assess the recovery and detection of genetic material from the enhanced fingermarks.We have shown that genetic profiling of bloodstained fingermarks can be successful after chemical enhancement; however it may still be necessary to prioritise evidence types in certain circumstances. From our results it appears that even with visible bloodstained fingermarks, leucocrystal violet can reduce the effectiveness of subsequent messenger RNA profiling. Aqueous amido black and acid yellow also have adverse effects on messenger RNA profiling of depleted fingermarks with low levels of cellular material. These results help with forensic decision-making by expanding knowledge of the extent of the detrimental effects of blood-enhancement reagents on both DNA profiling and body fluid identification using messenger RNA profiling.     

Case report of a homicide resolved 15 years later: The robustness of Chelex extraction

DNA typing techniques is one of the most advanced tools for human identification. During the last 10 years, a great number of methods for DNA extraction and analysis have been introduced to forensic genetic, with considerable success but also with considerable controversy. The success and validation of a criminal investigation are very closely related to the process used for obtaining and preserving biological evidence.We report the strategy that we employed to analyze evidences belonging to a homicide happened in Brescia (Italy) in 1992, not resolved at that time, with the forensic genetic analysis. After 16 years the analysis were conducted on DNA samples extracted with Chelex maintained at −80 °C, bloodstain, and biological specimens of perpetrators. Standard autosomal and Y-chromosome STR analysis identified the persons involved and victim's profiles. This case is of interest as a demonstration of a more successful application of DNA typing in well conserved DNA samples than in bloodstains kept in the Court Office.     

Molecular-genetic forensic expert investigations in the Russian Federation: problems and perspectives

Introduction of molecular-genetic technology into forensic-medical expert practice in Russia took place in unfavourable conditions of poor financial support and, consequently, the results appeared unsatisfactory. Organisation and functioning of genetic laboratories must be controlled and provided with an adequate system of training personnel and professional control. Application of molecular-genetic methods in forensic medicine meets the needs of expert practice if it is based on the systemic approach. The system is proposed to be headed by Russian Center for Forensic-Medical Expert Examination. This center is to update and control the activity of all institutions involved in forensic medical expert examination in Russia and conduct monitoring of the studies and training of specialists for the system.     

溺死诊断中浮游生物检验方法的研究现状及进展

法医学实践中,判断是否为生前溺死是法医学尸检及鉴定工作中的一个重点和难点,目前尚无能明确诊断溺死的生物学和法庭化学指标。在溺死案件的诊断中,浮游生物检验是常见的方法。尽管目前还存在一些争议,但国内法医工作者认为,器官组织中浮游生物的存在仍然是判断生前溺死的重要证据之一。本文就国内外有关浮游生物的检验方法、检验标准及检验结果的判定等研究现状作一综述,旨在使人们更加清晰地认识浮游生物检验在溺死诊断中的作用。     

植物物证的法医学应用

随着植物物证在案件侦破过程中的作用日益明显,应用植物学研究方法为刑事案件提供线索、证据的"法医植物学"越来越受到关注.法医植物学常用的实验技术有形态学检验、理化检验、分子遗传学检验等.本文通过整理法医植物学研究的相关文献及案例,以列举的形式简要阐述不同检验方法的利弊,总结法医植物学应用中需要注意的问题,供案件现场勘验时...     

The main results of expert activities in the forensic biological departments of the bureau of forensic medical expertise of the Russian Federation for 2009

This paper reports the main results of expert activities in the forensic biological departments of the Bureau of Forensic Medical Expertise of the Russian Federation for 2009. Analysis of expert data is supplemented by the comparison of the efficacy of the methods applied for the purpose of forensic medical studies. The information about the staff composition, material and technical support of the forensic biological departments is presented. A number of drawbacks have been revealed in the work of the forensic biological departments; recommendations are proposed for the improvement of their activities.     

Cerebral alcohol dehydrogenase-- a marker of individual ethanol tolerance in ethanol intoxication

Brain compartments differing by topical chemical location of alcohol dehydrogenases (ADH) were studied on forensic medical material. ADH were found in magnocytes of giant-cell reticular formation, neuronal nuclei in the blue spot, and capillaries, but not in neurons of the ganglionary layer of the cerebral limbic cortex. ADH activity in the studied brain compartments depended on the level of exogenous ethanolemia. Increased ADH activity in the reticular formation magnocytes characterized the individual tolerance in severe ethanol intoxication. Cerebral ADHs are markers of ethanol intoxication.     

From crime scene to courtroom: A review of the current bioanalytical evidence workflows used in rape and sexual assault investigations in the United Kingdom

Sexual assault casework requires the collaboration of multiple agency staff to formalise an investigative pipeline running from crime scene to court. While the same could be said of many other forensic investigations, few require the additional support of health care staff and the combined forensic involvement of body-fluid examiners, DNA experts and analytical chemists. The sheer amount of collaborative effort between agencies is laid out through a detailed examination of the investigative workflow from crime scene to courtroom with each step in the pipelines detailed and discussed. Beginning with a review of sexual assault legislation in the United Kingdom this article details how sexual assault investigations are initiated by police and supported by sexual assault referral centre (SARC) staff who are often the first responders providing primary healthcare and patient support to victims while simultaneously collecting and assessing forensic evidence. Detailing the myriad of evidential material that can be documented and collected at the SARC, the review identifies and categorises key forensic tests to first detect and identify body-fluids recovered from evidence through to the secondary analysis of DNA to help identify the suspect. This review also focusses on the collection and analysis of biological material used to support the allegation that the sexual activity was non-consensual and provides a breakdown of common marks and trauma as well as a review of common analytical methods used to infer Drug Facilitated Sexual Assault (DFSA). The culmination of the investigative pipeline is discussed by reviewing the Rape and Serious Sexual Assault (RASSO) workflow used by the Crown Prosecution Service before providing our thoughts on the future of forensic analysis and possible changes to the described workflows.     

Hyperspectral imaging in forensic science: An overview of major application areas

Analysis of evidence is a challenge. Crime scene materials are complex, diverse, sometimes of an unknown nature. Forensic science provides the most critical applications for their examination. Chemical tests, analytical methods, and techniques to process the evidence must be carefully selected by the forensic scientist. Ideally, it may be interpreted, analyzed, and judged in the original context of the crime scene. In this sense, hyperspectral imaging (HSI) has been employed as an analytical tool that maintains the integrity of the samples/objects for multiple and sequential analysis and for counter-proof exams. This paper is an overview of forensic science trends for the application of HSI techniques in the last ten years (2011–2021). The examination of documents was the main area of exploration, followed by bloodstain analysis aging process; trace analysis of explosives and gunshot residue. Chemometric tools were also addressed since they are crucial to obtain the most important information from the samples. There are great challenges in applying HSI in forensic science, but there have been clear technological and scientific advances, and a solid foundation has been built for the use of HSI in real-life cases.     

The advantages of establishing the species classification of blood and other biological objects by the IFR in a quantitative modification

A quantitative modification of immunofluorescent test (IFT) is described. It was used for species identification of blood stains on material evidence objects. This modification is 1000 times more sensitive than electrophoretic methods traditionally used for this purpose in forensic medicine. Computer processing of the results helps objectively and persuasively determine the species appurtenance of blood and other biological objects. Results of the test represented as histograms should be attached to forensic medical conclusions as proofs for the court.     

家庭暴力受虐妇女法医学鉴定69例分析

家庭暴力虐待妇女的法医学鉴定近年来在临床检案中较常见，但国内法医文献报道甚少。家庭暴力不仅严重损害了妇女的身体，而且给其心理、精神上造成创伤，这已引起社会的普遍关注。从法医学角度看，加强对受虐妇女的检验、调查、取证工作与研究具有重大意义。本文收集１９９３年１月至１９９５年１２月的６９件案例进行分析，并对有关问题进行初步探讨。     

Mitochondrial DNA sequencing of human hair shafts stored for long time

Mitochondrial DNA (mtDNA) sequencing is commonly used for forensic genetic identification of relation and personality identification based on analysis of tooth and skeletal rudiments. We demonstrated the possibility of DNA extraction and subsequent enzymatic amplification of fragments of a hypervariable segment I of mtDNA control region from hair shafts after long storage (up to 75 years). Shed hairs are the most common biological material evidence in forensic investigations. Low content of DNA and its possible degradation in hair shafts without bulbs may cause artifacts in polymerase chain reaction. However comparative analysis of amplified nucleotide sequences of amplified fragments from hair stored for 75 years was identical to the sequence from hairs cut immediately before experiment. This indicates high quality of the resultant matrices, stability of results, and hence, the possibility of using DNA extracted from hair shafts without bulbs stored for a long time for expert genetic analysis. Theoretical and methodological prospects of using mtDNA polymorphism analysis for forensic expert evaluations are discussed.     

Illuminating the benefits and limitations of forensic light sources

Forensic light sources, such as a Crime-lite, are used in forensic laboratories and by police staff in the examination for, and detection of, biological material. Whilst the benefits of using forensic light sources are relatively well understood, their limitations are less-so. This report details the outcome of studies, validation and review by three forensic laboratories, as well as three case examples, to highlight both the strengths and weaknesses of the tested forensic light sources and to demonstrate that, whilst a useful preliminary screening tool, they should not be used in isolation without subsequent presumptive chemical testing. False positives and negatives are common, and the background substrate and specific biological material present can have a significant effect on the outcome of examination when using a forensic light source.     

Sexual assault examinations and forensic medical samples

Recent studies and a review in the United States have identified that tens of thousands of used but untested sexual assault examination kits containing medical examination specimens are to be found in police station evidence rooms, forensic science laboratories, hospitals and rape crisis centres. A 2007 survey undertaken by the National Institute of Justice in the United States explored some of the reasons why forensic specimens are not tested by forensic science laboratories. Many of these relate to lack of knowledge on the part of investigators as to how scientific information can assist the investigation process, even if not used subsequently at trial. Cost factors and laboratory casework overload were also identified as significant. For the medical practitioner, the lack of testing poses issues that include quality management of the forensic medical examination and informed consent in a setting requiring the balancing of public and private benefits for the examinee. Limiting scientific testing, even with intelligence-led triaging of sample testing, could have an adverse effect on both prosecution and defence decision-making and ultimately could adversely affect trial outcomes.     

Isolation and Individualization of Conceptus and Maternal Tissues from Abortions and Placentas for Parentage Testing in Cases of Rape and Abandoned Newborns*

Abstract: Abortion specimens are often submitted to forensic laboratories as the only piece of physical evidence in rape and incest cases. The recovery of conceptus tissues from this evidence permits the use of paternity testing to evaluate suspects. In cases of abandoned newborns, the recovery of maternal tissue from the placenta allows for the direct comparison of genetic profiles between the suspected mother and the biological mother. We report on the identification and isolation of conceptus tissues from embryonic‐ and fetal‐period abortions, and maternal tissues from delivered placentas, by gross and low‐magnification examination with manual dissection. Hundreds of single‐source samples have been successfully recovered by this method and short tandem repeat typed using standard forensic procedures. We additionally describe extraembryonic tissues that can be recovered and typed in the absence of the embryo proper. We conclude that an expertise and protocols can be developed by forensic laboratories for the routine analysis of this evidence.     

The need of regulation of production of components for forensic-medical molecular-genetic technologies and improvement of legal basis of forensic-medical molecular-genetic expert examinations in the Russian Federation

Of late, Ministry of Health of Russian Federation has developed instructions concerning forensic-medical molecular genetic methods of analysis promoting creation of standardized forensic-medical genetic service. However, some legal uncertainty exists in respect to design and production of the materials for forensic-medical molecular-genetic technologies, unification and standardization of molecular-genetic kits and methods. It is thought necessary to regulate legally forensic medical molecular-genetic technologies from foreign countries and production and use of domestic components for forensic medical molecular-genetic expert examinations.     

The reliability of forensic osteology--a case in point. Case study

The medico-legal investigation of skeletons is a trans-disciplinary effort by forensic scientists as well as physical anthropologists. The advent of DNA extraction and amplification from bones and teeth has led to the assumption that morphological assessment of skeletal remains might soon become obsolete. But despite the introduction and success of molecular biology, the analysis of skeletal biology will remain an integral part of the identification process. This is due to the fact, that the skeletal record allows relatively fast and accurate inferences about the identity of the victim. Moreover, a standard biological profile may be established to effectively narrow the police investigator's search parameters. The following study demonstrates how skeletal biology may collaborate in the forensic investigation and support DNA fingerprinting evidence.In this case, the information gained from standard morphological methods about the unknown person's sex, age and heritage immediately led the police to suspect, that the remains were that of a young man from Vietnam, who had been missing for 2.5 years. The investigation then quickly shifted to prove the victim's identity via DNA extraction and mtDNA sequence analysis and biostatistical calculations involving questions of kinship [4].