A 1-year time course study of human RNA degradation in body fluids under dry and humid environmental conditions

Blood, saliva and semen are some of the forensically most relevant biological stains found at crime scenes. mRNA profiling is a reliable approach for the identification of the origin of an evidentiary trace. A stable set of markers and the knowledge about the effects of RNA degradation under different environmental conditions is necessary for the determination of an unknown biological stain. The aim of this work was to compare RNA degradation for human blood, semen and saliva at three different concentrations during a 1-year time period and exposed to dry and humid conditions. Also, this study addressed the question whether there are relevant differences in the efficiency of two RNA extraction methods.     

Multiplex high resolution melt (HRM) messenger RNA profiling assays for body fluid identification

Traditional body fluid identification methods use a variety of technologically diverse techniques that do not permit the identification of all body fluids. Definitive identification of the biological material present can be crucial to a fuller understanding of the circumstances pertaining to a crime. Thus definitive molecular based strategies for the conclusive identification of forensically relevant biological fluids need to be developed. Messenger (mRNA) profiling is an example of such a molecular based approach.Current mRNA body fluid identification assays typically involve either capillary electrophoresis (CE) or quantitative RT-PCR (qRT-PCR) platforms, each with its own limitations. Both platforms require the use of expensive fluorescently labeled primers or probes. CE-based assays require separate amplification and detection steps thus increasing the time required for analysis. For qRT-PCR assays, only 3 or 4 markers can be included in a single reaction since each requires a different fluorescent dye. To simplify mRNA profiling assays and to reduce the time and cost of analysis, we have developed multiplex high resolution melt (HRM) assays that provide an identification of all forensically relevant biological fluids and tissues.     

The efficiency of Y-chromosome markers in forensic trace analysis and their inclusion in the Austrian National DNA Database

Y-STR markers are a valuable tool in the analysis of biological traces in which a mixture of male and female trace material is to be expected. It is possible to generate a Y-chromosome DNA profile, even if all the prior sperm tests are negative and no sign of any male component is found in amelogenin. In 38 of a total of 239 sexual offences a perpetrator trace was identified solely using Y-STR analysis. Based on these findings, the Austrian National DNA Database was expanded to include Y-STRs in 2012 with the primary objective to identify serial sexual offences.     

Evaluation of five DNA extraction systems for recovery of DNA from bone

Five DNA extraction systems were assessed for their DNA extraction efficiency on samples of fresh pig bone. Four commercially available silica-based extraction kits (ChargeSwitch^® gDNA Plant Kit (Life Technologies), DNA IQ^TM System Kit (Promega), DNeasy^® Blood & Tissue Kit (Qiagen) and PrepFiler^® BTA Forensic DNA Extraction Kit (Life Technologies)) and a conventional phenol-chloroform method were tested in this study. Extracted DNA samples were quantitated with GoTaq^® qPCR Master Mix (Promega) using an Applied Biosystems^® 7500 Real-Time PCR System and the extracts were amplified using an in-house multiplex system. The phenol-chloroform extraction produced higher yields of DNA than the silica-based extraction methods. Among the silica-based extractions ChargeSwitch^® gDNA Plant Kit recovered the highest amounts of DNA. However, all methods produced DNA that could be amplified and none of the extracts contained any detectable inhibition.     

Development of 30 InDel markers typing system and genetic analysis in five different Chinese populations

Allele frequencies of 30 InDel markers previously selected and validated for forensic purpose were assessed in 419 unrelated individuals originating from five different populations of Chinese Han, Chinese Hui, Uighur, Mongolian and Tibetan in P.R. China. Hardy–Weinberg equilibrium tests and linkage disequilibrium analysis were performed and the results showed that allele frequency distributions of the 30 InDel markers had meet the genetic equilibrium in all of the five populations and the InDel markers on same chromosome did not generate any linkage block. Analysis of molecular variance (AMOVA) indicated that genetic variation among the 5 studied populations represent only 4.00% of the total genetic diversity. We observed the cumulative power of discrimination (CPD) for each studied population was 0.99999999999841 in Chinese Han population, 0.99999999999690 in Chinese Hui population, 0.99999999999709 in Uighur population, 0.99999999999772 in Mongolian population and 0.99999999999854 in Tibetan population.     

Genetic polymorphisms of 20 STR loci in Chinese Han population in Tianjin,North China

The PowerPlex^® 21 System PCR Amplification Kit was a new PCR Amplification Kit developed for forensic laboratories, but there was a lack of data about this kit in Chinese people in Tianjin, North China. This kit contained 20 STR loci, D3S1358, D1S1656, D6S1043, D13S317, Penta E, D16S539, D18S51, D2S1338, CSF1PO, Penta D, TH01, vWA, D21S11, D7S820, D5S818, TPOX, D8S1179, D12S391, D19S433 and FGA. In order to evaluate this kit and to get basic population data for its use in forensic practice in Chinese Han population, 360 unrelated Chinese Han individuals from Tianjin were typed using the Kit. Allele frequencies of the 20 STR loci and further population forensic genetic parameters were obtained. The observed genotype frequencies and expected genotype frequencies were evaluated by χ² test. No significant deviation from the Hardy–Weinberg equilibrium was observed in the population sample for the 20 STR loci. The population data in the present study can be used for routine forensic practice in Tianjin, North China.     

强奸案件的法医学取证探讨

强奸犯罪是一种相对隐蔽的犯罪,通常是在没有第三人在场的情况下发生,因此作为证据的法医物证尤为重要。法医学的规范正确取证及物证分析,对侦破强奸案件、识别伪造和诬陷强奸案具有重要意义。     

少女积极杀婴2例

目的：分析少女积极杀婴案中婴儿的死亡原因。方法：通过对2例积极杀婴案进行分析,得出婴儿死亡原因。结果：两个案例中的婴儿均为发育正常新生活产儿。结论：积极杀婴案中嫌疑人均为少女,受教育程度低,急于想把新生儿在不为人知的情况下处理掉,而采用溺死、高坠等方法造成婴儿死亡,因此,应加强偏远地区及农村的青少年性与生殖健康方面知识的教育。     

The “Bestie di Satana” Murders

In recent years, satanic groups have been responsible for various types and degrees of crimes. We report the case of a number of murders committed in Italy by a group of young people calling themselves the “Bestie di Satana”. Forensic psychiatric assessment of the members of a satanic sect charged with the crime revealed that all the young people had a fragile, immature personality, a very low level of education and were socially disadvantaged. The trial of the members of the “Bestie di Satana” sect was concluded with the verdict of deliberate murder, and all the members were given long jail sentences. This report should lead us to explore social and cultural responses to juvenile satanism, statistically shown to be a relatively rare phenomenon but with a high criminal potential.     

中国成都地区汉族群体5个STR基因座的遗传多态性

采用PCR扩增,聚丙烯酰胺凝胶电泳分析技术,调查中国成都汉族群体DIS1656、D851179、D9S302、D185535及D195253等5个STR基因座的等位基因频率分布。D1S1656检出11个等位基因,35种基因型;DSS1179检出9个等位基因,32种基因型;D95302检出12个等位基因,50种基因型;D185535检出7个等位基因,20种基因型;D195253检出8个等位基因,28种基因型。5个STR基因座基因型频率分布符合Hardy-weinberg平衡（P＞0．05）。个人识别机率（DP）为0．92～0．98。分析了二代3口之家的遗传模式,证明5个STR基因座均符合孟德尔遗传规律。5个STR基因座PCR扩增采用同一条件,方法简单、快速、灵敏、重复性好,可用于法科学亲子鉴定和个人识别。