Quantitative analysis of amplifiable DNA in tissues exposed to various environments using competitive PCR assays

Competitive PCR assays were established for the mitochondrial DNA hypervariable region I and the human amelogenin locus. Using these assays, the copy numbers of DNA participating in PCR (amplifiable DNA) were quantified in tissues exposed to different environments. Human ribs, skin and nails were left in three exposure conditions (in the open air, in soil and in water). The amounts of amplifiable DNA in these tissues were quantified during a time period of up to two months. The amount of amplifiable DNA was well preserved in hard tissues (ribs and nails) regardless of the exposure conditions, whereas the soft tissues immersed in water showed a rapid decrease in amplifiable DNA. Strong PCR inhibition was observed in the DNA extracts obtained from buried bones. This phenomenon was clearly identified from an amplification failure of the internal standards in the competitive PCR. A preliminary examination to identify the PCR inhibitor suggested that the soil itself contributed to the inhibition. In addition, the amounts of amplifiable DNA in case samples were also investigated.     

6FAM-HEX-TMR-ROX四色荧光分析体系的构建

目的为在310基因分析仪上进行6FAM-HEX-TMR-ROX四色荧光STR复合扩增分型建立基础条件。方法以pGEM载体作为靶DNA,设计引物扩增获得500~80bp的13个长度不等DNA片段,以这些片段纯化物作为模板DNA,分别扩增获得6FAM、HEX、TMR和ROX标记的M atrix标准物,用4种M atrix标准物在310基因分析仪上构建可用于6FAM-HEX-TMR-ROX四色荧光分析的M atrix文件。结果扩增所得的13个非标记片段,长度分别为80、100、120、140、160、180、200、220、260、300、340、400、500bp,在非变性聚丙烯酰胺凝胶连续电泳-银染凝胶上均表现为单条带,6FAM、HEX、TMR、ROX分别标记的片段通过310基因分析仪检测均为单峰。混合ROX标记的80、120、180、220、260、300bp的6个片段获得的内标,显示出良好的线性关系。结论建立了有效的6FAM-HEX-TMR-ROX四色荧光分析M atrix,为进行多个STR基因座荧光标记复合扩增检测奠定了基础。     

驯鹿狂蝇生活习性的观察

对感染驯鹿狂蝇幼虫驯鹿进行了剖检观察,证实狂蝇幼虫主要寄生于驯鹿鼻腔及咽喉黏膜,在当年的7月到翌年1月主要以一期幼虫为主,从翌年2～3月开始快速生长发育,在4～6月多为二、三期幼虫。从翌年5月开始,成熟的三期幼虫随驯鹿打喷嚏排出体外羽化为成蝇。通过对驯鹿狂蝇生活史的观察,表明在大兴安岭地区,驯鹿狂蝇三期幼虫在50％～70％的湿度、21．5℃的平均温度及21．5℃下的451．5～666．5℃总积温下,经21-31 d羽化为成蝇,羽化率为59．6％。成蝇出现于6-9月份,在7～8月份达高峰期。驯鹿狂蝇1年发生一个世代,在驯鹿体内的寄生生活长达9-10个月;雌性成蝇每次产胎蚴30-80条,一生共产800-1000条;雌蝇寿命比雄蝇长,约为1-3周。     

指印生物遗传标记检验的研究现状与展望

综述了血指印和汗潜指印生物遗传标记的研究历史和现状,指印DNA检验面临的问题,包括现场污染,显现剂的影响,载体的影响等,并对指印DNA在法医学中的应用前景进行了展望。     

珍灵口服液的主要药效与毒性研究

目的：对珍灵口服液进行主要药效及毒性研究。方法：采用酶联免疫吸附（ELISA）测定小鼠血清中IgG含量，采用植物血凝素（PHA）刺激淋巴细胞转化－－小鼠体内诱导法测定淋巴细胞转化率；用TBA反应比色法测定小鼠血清中脂质过氧化物（LPO）的含量，用NBT法（四氮唑蓝法）测定超氧化物歧化酶（SOD）的含量；并进行了急性和长期毒性试验。结果：小鼠血清IgG含量、淋巴细胞数、红细胞内SOD含量明显升高（P＜0．05或P＜0．01）；血清中LPO含量明显降低（P＜0．05）；未见毒性反应。结论：珍灵口服液能增强机体免疫力，并具有降低机体损伤的功能，是安全有效的保健药品。     

微量生物检材常规初检后再行PCR检验的方法

在实际检案中，经常遇到案发现场可获取的生物检材量微，在进行必要的种属检验、精斑确证实验、ABO血型检验等常规物证初检后，便无多余的生物检材移送DNA实验室进一步做法医DNA检验。因此，笔者通过对检案中遇到的上述微量物证检材的再行处理利用，在本实验室条件下，对其进行了TH０１、HUMACTBP２、AluVpA、DIS８０等位点的DNA－PCR分析，获得了良好的效果。使其在实际办案中更充分地发挥了证据作用，报告如下。１材料与方法检案中已经种属或ABO血型检验后的血痕、唾液斑（如烟蒂外层纸）浸泡凹板，加入３００μl去离子水，…     

口蹄疫病毒多基因片段的克隆及其杆状病毒表达载体的构建

根据定点突变原理获得了包含口蹄疫病毒P1、2A、3C、3D及部分 2B编码区的目的基因片段 ,经SpeⅠ和HindⅢ双酶切后 ,与经相同方法处理的杆状病毒转移载体 pFastBacHT连接 ,得到了重组质粒 pFB P12X3C3D。经酶切和测序鉴定后 ,将其转化入含穿梭载体Bacmid的感受态细胞DH10Bac ,经抗性及蓝白斑筛选 ,得到了含P12X3C3D多基因的重组穿梭载体 ,将其命名为Bacmid P12X3C3D ;提取其DNA并转染Sf9昆虫细胞 ,最后获得含口蹄疫病毒P12X3C3D多基因的重组杆状病毒。     

退耕还林保护西部生态环境

生态环境的恢复与建设是我国西部大开发的首要任务.在保护生态、改善环境、发展经济的过程中,要特别重视退耕还林(草)等对保护西部生态环境的作用.我们要根据<全国生态环境建设规划>以及可持续发展的要求,采取相应的对策.     

纸张上潜在手印三种前处理方法对DNA检验的影响

目的通过比较常见纸张上潜在手印盲提法与显现后精准提取法的接触DNA检出率,探讨常见纸张上接触DNA前处理的优选方案。方法比较五种常见纸张上使用盲提法和显现潜在手印(茚二酮显现法、茚三酮熏显法)后精准提取法采集的接触DNA样本检出率。结果粗糙日历纸盲提的接触DNA检出率为17.8%,通过茚二酮法和茚三酮法显现的潜在手印所提取的DNA检出率分别为75.6%、77.8%;光滑日历纸三种方法所提取的接触DNA检出率为4.4%、11.1%、11.1%;A4复印纸三种方法接触DNA检出率为20%、37.8%、66.7%;牛皮纸三种方法接触DNA检出率为20%、68.9%、64.4%;快递纸袋的三种方法接触DNA检出率为2.2%、6.7%、46.7%。结论不同纸张上潜在手印经显现后接触DNA检出率不同,通过茚二酮或茚三酮显示潜在手印后精准提取DNA的前处理方法相较于盲提法的接触DNA检出率高。实战中可应用此类方法同时获得手印与DNA分型,以有效提高证据力。     

The effectiveness of forensic evidence in the investigation of volume crime scenes

This study investigates the effectiveness of forensic evidence in UK volume crime investigations. The main aim was to identify characteristics of forensic evidence that influence its effectiveness in converting detections into criminal charges, as well as to critically consider the effectiveness of a recent service level agreement (SLA) implemented by Wiltshire Police, which aimed at reducing CSI attendance. The sample consisted of 445 police recorded cases received from Wiltshire Police. Presence or absence and location-related characteristics of fingerprint, DNA, and footwear evidence were evaluated on the effectiveness of forensic evidence and examined within the contexts of different volume crimes. Results showed a high level of correlation in converting detections into criminal charges where the presence of DNA, footwear, and multiple evidence types was recorded; and a positive correlation between forensic evidence ineffectiveness and presence of fingerprints, particularly in residential burglaries. Differences between individual offence types were expressed. The most prominent feature influencing the effectiveness of forensic evidence was found to be related to the movability of the exhibit associated with the recovered evidence, with DNA recovered from non-movable items presenting the strongest effectiveness. Cases processed after the implementation of the SLA did not show significant differences in forensic evidence effectiveness as compared to cases processed prior to the SLA, however, they demonstrated a lack in effectiveness of DNA evidence. The findings of the current research provide a better understanding of the contextual influences on the potential of forensic evidence and can support improvement of crime scene screening and CSI resource deployment.