签名笔迹量化检验研究用实验样本的设计与收集

本文在全面说明签名笔迹特点的基础上，阐述了签名笔迹特征层次结构模型的核心内容，重点探讨开展签名笔迹量化检验研究用实验样本的方案设计，收集方法与范围。同时，提出实验样本的设计与搜集应本着“贴近实战，服务办案”的原则，并具体设计了签名笔迹量化检验研究用实验样本的设计方案与具体内容，提出广泛收集具有代表性实验样本的具体要求。另外，提出了研究用实验样本筛选方法和扫描输入计算机具体要求。科学合理的设计与收集签名笔迹量化检验研究用实验样本，才能确保签名笔迹量化检验研究具体分析与统计结果的科学性和实用性。     

脱落上皮细胞类生物检材的自动化提取

目的建立一种自动化提取脱落上皮细胞类生物检材DNA的方法。方法附着于不同载体上的脱落上皮细胞类生物检材共278份,应用Eppendorf epMotion 5075LH工作站结合DNA IQTM系统提取模板DNA,并用Identifiler试剂盒进行STR检验。结果在278份被检的生物检材,其中126份检材获得13个基因座以上的STR分型,不同类型的检材其检出率不相同,最高达73.44%,最低为10.89%。结论脱落上皮细胞类检材应用自动化工作站提取DNA模板可在法医日常检案中广泛应用。     

扩增TP53内含子8用于生物检材的种属鉴定

目的扩增常见动物TP53内含子8片段,确定其在法医学生物检材种属鉴定中的应用价值。方法收集标本为包括人在内的15种常见动物的血痕或肌肉组织,提取DNA后定量,应用PCR扩增TP53内含子8,PAGE电泳,银染后观察结果。结果人和猕猴都扩增出一条长度为460bp的片段,鳝鱼、鲢鱼、青蛙、鸭、兔、猫、小白鼠、豚鼠、猪、牛、羊虽有扩增产物,但不在分型区内,鸡、狗未见扩增产物。结论扩增TP53内含子8进行种属鉴定,方法简单,灵敏度较高。     

生物检材中海洛因代谢物分析现状

海洛因在体内极易代谢,其主要的代谢产物为单乙酰吗啡、吗啡等。目前,检测海洛因代谢物的常用生物检材有尿液、血液、毛发等;常用分析方法有薄层色谱法、气相色谱法、高效液相色谱法、气相色谱-质谱联用法、液相色谱-质谱联用法、免疫分析法、毛细管电泳法等。本文参考近年来的文献对生物检材中海洛因代谢物的分析方法作一综述,为法医毒物分析等相关领域的研究提供参考。     

苓桂术甘汤对免疫功能低下模型小鼠淋巴细胞活性的影响

目的:观察苓桂术甘汤对免疫功能低下模型小鼠免疫功能的影响.方法:近交系昆明种小鼠以环磷酰胺(Cy,80 mg/kg,ip,qd×1)诱导免疫功能低下,用苓桂术甘汤(42.90,21.45,4.29 g/kg)连续灌胃(ig)给药7 d,分别采用免疫溶血法、四氮唑盐比色法(MTT)和小鼠胸腺细胞氚标胸腺嘧啶核苷(3H-TdR)掺入法测定血清溶血素、NK细胞及IL-2活性.结果:苓桂术甘汤能明显促进Cy所致免疫功能低下模型小鼠血清溶血素生成,增强NK细胞及IL-2活性,与模型组比较,差异有显著性(P＜0.05或P＜0.01).结论:苓桂术甘汤对Cy所致免疫功能低下模型小鼠三类淋巴细胞的免疫活性均具有明显的激活作用.     

Analyzing degraded DNA and challenging samples using the ForenSeq™ DNA Signature Prep kit

Typing short tandem repeats (STRs) is the basis for human identification in current forensic testing. The standard method uses capillary electrophoresis (CE) to separate amplicons by length and fluorescent labeling. In recent years new methods, including massively parallel sequencing (MPS), have been developed which increased the discriminative power of STRs through sequencing. MPS also offers the opportunity to test more genetic markers in a run than is possible with standard CE technology. Verogen’s ForenSeq™ DNA Signature Prep kit includes over 150 genetic markers [STRs and single nucleotide polymorphisms (SNPs)]. Further, MPS separation depends on sequences rather than lengths; therefore, amplicons can be small or even of the same lengths. These improvements are advantageous when testing challenging forensic samples that could be severely degraded.This study tested the ForenSeq™ DNA Signature Prep kit in repeated experimental runs on series of degraded DNA samples, ranging from mild to severe degradation, as well as 24 mock case-type samples, derived from bones, blood cards, and teeth. Despite passing the quality metrics, positive controls (2800 M) showed drop-outs at some loci, mostly SNPs. Sequencing DNA samples repeatedly in two experimental runs as well as sequencing one pooled library in triplicate led to the assumption that spurious alleles of the Y-STRs in this study were not a result of sequencing artifacts but could be due to sequence structures (e.g. duplications, palindromes) of the Y-chromosome and/or might be accumulated during library preparation.Two sets of serially degraded DNA samples revealed that dropped-out loci were primarily loci with long amplicons as well as low read numbers (coverage), e.g. PentaE, DXS8378, and rs1736442. STRs started to drop out at degradation indices (DIs) > 4. However, severely degraded DNA (DI: 44) still resulted in 90% of the 20 CODIS loci, while only 35% were obtained using Promega’s PowerPlex® Fusion kit, a current standard CE kit. Mock case-type samples confirmed these results. ForenSeq™ DNA Signature Prep kit demonstrated that it can be successfully used on degraded DNA samples. This study may be helpful for other laboratories assessing and validating MPS technologies.     

微量生物物证提取套装在现场微量血痕DNA检验中的应用

目的 探讨微量生物物证提取套装应用于提取现场微量血痕DNA的检验效果.方法 将静脉血制成地面血痕.分别应用微量生物物证提取套装法和普通法提取血痕.分别于恒温摇床放置2、24、48、72、96 h(每组50份)进行血痕DNA检验,对比各组检验结果.结果 恒温摇床上分别放置24、48、72、96 h后,微量生物物证提取套装...     

The Potential of Cosmetic Applicators as a Source of DNA for Forensic Analysis

Personal products, such as toothbrushes, have been used as both known reference and evidentiary samples for forensic DNA analysis. This study examined the viability of a broad selection of cosmetic applicators for use as targets for human DNA extraction and short tandem repeat (STR) analysis using standard polymerase chain reaction (PCR) conditions. Applicator types included eyeliner smudgers, pencils and crayons, eye shadow sponges, mascara wands, concealer wands, face makeup sponges, pads and brushes, lipsticks and balms, and lip gloss wands. The quantity and quality of DNA extracted from each type of applicator were examined by assessing the number of loci successfully amplified and the peak balance of the heterozygous alleles in each full STR profile. While degraded DNA, stochastic amplification, and PCR inhibition were observed for some items, full STR profiles were developed for 14 of 76 applicators. The face makeup sponge applicators yielded the highest proportional number of full STR profiles (4/7).     

血清氟含量测定在溺死诊断上的意义

考虑到广东的水含氟量高,本文测定了溺死兔的血清氟含量,并与缢死后入水浸泡兔的血清氟含量进行对比。水中氟含量大约比正常人和动物血清氟高15倍。溺死后兔血清氟含量明显高于溺死前。相反,在对照的死后浸泡兔的血清氟含量稍低于死前。人与兔的血清氟含量相近。这提示,血清氟含量测定对高氟区的溺死诊断是有价值的。     

两种包装方式对小体积生物检材DNA检验的影响

目的探讨一种适用于小体积生物物证检材的包装方式。方法选择M4型螺丝钉作为研究对象,经去污消毒处理,通过手握方式转移人体脱落细胞到其表面,对螺丝钉采用两种不同的包装方式(滤纸包裹和悬空固定),经KingFisher Flex自动提取工作站进行DNA提取,从基因座等位基因检出情况、STR分型谱带峰高、均衡性等方面比较两种包装方式对螺丝钉上DNA检出率的影响。结果悬空固定包装螺丝钉实验组获得的STR分型谱带峰高、均衡性等方面均优于滤纸包裹包装实验组,其在基因座检出数量、分型完全相同样本数及有效分型样本数方面也多于滤纸包裹包装实验组。结论为降低微量生物检材DNA二次转移造成的损耗,提高小体积生物检材DNA的检出率,建议对小体积生物检材采用悬空固定方式进行物证包装。