TrueAllele® Genotype Identification on DNA Mixtures Containing up to Five Unknown Contributors

Computer methods have been developed for mathematically interpreting mixed and low‐template DNA. The genotype modeling approach computationally separates out the contributors to a mixture, with uncertainty represented through probability. Comparison of inferred genotypes calculates a likelihood ratio (LR), which measures identification information. This study statistically examined the genotype modeling performance of Cybergenetics TrueAllele^® computer system. High‐ and low‐template DNA mixtures of known randomized composition containing 2, 3, 4, and 5 contributors were tested. Sensitivity, specificity, and reproducibility were established through LR quantification in each of these eight groups. Covariance analysis found LR behavior to be relatively invariant to DNA amount or contributor number. Analysis of variance found that consistent solutions were produced, once a sufficient number of contributors were considered. This study demonstrates the reliability of TrueAllele interpretation on complex DNA mixtures of representative casework composition. The results can help predict an information outcome for a DNA mixture analysis.     

An Accelerated Analytical Process for the Development of STR Profiles for Casework Samples

Significant efforts are being devoted to the development of methods enabling rapid generation of short tandem repeat (STR) profiles in order to reduce turnaround times for the delivery of human identification results from biological evidence. Some of the proposed solutions are still costly and low throughput. This study describes the optimization of an analytical process enabling the generation of complete STR profiles (single‐source or mixed profiles) for human identification in approximately 5 h. This accelerated process uses currently available reagents and standard laboratory equipment. It includes a 30‐min lysis step, a 27‐min DNA extraction using the Promega Maxwell^®16 System, DNA quantification in <1 h using the Qiagen Investigator^® Quantiplex HYres kit, fast amplification (<26 min) of the loci included in AmpF?STR^® Identifiler^®, and analysis of the profiles on the 3500‐series Genetic Analyzer. This combination of fast individual steps produces high‐quality profiling results and offers a cost‐effective alternative approach to rapid DNA analysis.     

法医DNA分析的其他应用

综述了法医DNA的多种用途,如人死后根据体内DNA变化情况推断死后时间间隔,利用线粒体DNA4977bp的缺失以及端粒的长度推断年龄;利用昆虫mtDNA的细胞色素氧化酶亚基I进行昆虫种属鉴定,以帮助确定人的腐尸死亡时间;利用一些食血昆虫体内的人DNA帮助了解与案件的关系;利用DNA标记进行动物如犬、牛、马及猪等个体识别与亲子鉴定,解决因动物引起的纠纷,或者利用DNA分析嫌疑人周围的动物毛发、植物及土壤微生物等,确定嫌疑人与案件的关系。     

The collation of forensic DNA case data into a multi-dimensional intelligence database

The primary aim of any DNA Database is to link individuals to unsolved offenses and unsolved offenses to each other via DNA profiling. This aim has been successfully realised during the operation of the New Zealand (NZ) DNA Databank over the past five years. The DNA Intelligence Project (DIP), a collaborative project involving NZ forensic and law enforcement agencies, interrogated the forensic case data held on the NZ DNA databank and collated it into a functional intelligence database. This database has been used to identify significant trends which direct Police and forensic personnel towards the most appropriate use of DNA technology. Intelligence is being provided in areas such as the level of usage of DNA techniques in criminal investigation, the relative success of crime scene samples and the geographical distribution of crimes. The DIP has broadened the dimensions of the information offered through the NZ DNA Databank and has furthered the understanding and investigative capability of both Police and forensic scientists. The outcomes of this research fit soundly with the current policies of 'intelligence led policing', which are being adopted by Police jurisdictions locally and overseas.     

浅谈我国法庭科学DNA数据库的建设

国家法庭科学DNA数据库充分地显示了DNA的技术效力 ,具有极其广阔的应用前景。DNA数据库在实践中的应用 ,带来了巨大社会效益和经济效益 ,是公安工作现代化的需要 ,因此 ,在我国建立国家法庭科学DNA数据库具有重要性和紧迫性 ,同时也具有可行性 ,但需要法庭科学DNA实验室、法律界、政府、立法者之间的全面合作。     

从聚丙烯酰胺凝胶中回收DNA片段直接PCR的简易方法

将聚丙烯酸胺凝胶中ＤＮＡ片段于ＰＣＲ缓冲液中电洗脱，加入ＰＣＲ反应试剂，直接扩增目的ＤＮＡ作进一步分析，ＤＮＡ片段回收效率为０．８９±０．０５，本方法简便、快速。     

单亲亲子鉴定及其法律问题思考--附275例单亲鉴定分析

目的探讨单亲鉴定及其有关的法律及社会问题. 方法对1998年1月至2002年12月275例单亲鉴定进行回顾分析,对案例的数量、来源、鉴定事由、鉴定结论等作统计分析. 结果单亲鉴定近3年明显增多,占亲子鉴定总数的三成.案例来源以自诉为主,占95.27%.鉴定事由中,怀疑妻子有婚外性关系为主 ,占88.36%.275例单亲鉴定中,排除亲生关系39例,占14.18%.结果表明,非婚生子女只占少数. 结论自诉单亲鉴定存在法律盲区,但在维护家庭稳定具有一定作用.受理单亲鉴定宜取慎重态度,有关的社会及法律问题需要解决.     

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。     

DNA技术在系列案件串并中的应用

系列案件、流窜案件时空跨度大,严重影响社会稳定。对其进行及时的串并侦查是一项有效的侦查措施。DNA技术和DNA数据库目前已越来越多地应用于凶杀、强奸、盗窃、抢劫等许多系列案件的串并和认定,为最大限度打击犯罪,合理配置有限的侦查资源提供了强有力的科技支撑。