利用AP-PCR对柔嫩艾美球虫不同地理株及其杂交株多态性的研究

用随机引物PCR(AP PCR)技术对鸡柔嫩艾美球虫(Eimeria tenella)黑龙江株(H)、山东株(S)及黑龙江株与山东株的杂交株(F1)进行了研究,同时对 2 个不同地理株的子代株与亲代株和F1 株的亲缘关系进行了分析。结果,鸡柔嫩艾美球虫不同地理株之间以及同一地理株的亲代与子代之间存在DNA多态性;并且不同地理株间的种内变异程度较大(Si=0.642 3~0.637 0);同一地理株亲代与子代之间的亲缘关系也稍有改变,但其变异程度不大(Si=0.983 0~0.981 1)。对F1 株的AP PCR分析发现,F1 株与H株、S株的相似值分别为0.692 9、0.682 5,介于H株与S株相似值和传代株间的相似值之间。结果表明,F 株既具有两亲本株的遗传性状,又发生了变异。     

一种简便的DNA提取方法在动物毛发检验中的应用

目的建立一种简便的DNA提取方法,用于动物毛干的DNA抽提。方法利用PCR缓冲液及蛋白酶K在PCR仪上对毛发进行消化,以此DNA为模板,扩增mtDNA 12S rRNA基因的部分片段并进行序列测定,测序结果在GenBank上进行BLAST搜索,再利用DNAMAN软件进行同源性分析。结果利用这种新DNA抽提法能从无毛囊毛发中获得后续PCR扩增所需的线粒体DNA。结论该法在无毛囊毛发样本鉴定中具有较高的应用价值。     

利用DNA和RNA进行死亡时间推断的研究进展

死亡时间是法医和刑事侦查工作者在调查犯罪行为和其他死亡事件中所需要的重要信息之一。但是目前死亡时间推断所使用的传统方法常受到经验和环境的影响，从而降低推断的准确性。由于DNA和某些RNA在细胞内的含量十分稳定，而且个体死亡后这些遗传物质随着死亡时间的延长呈有规律地降解，所以通过测定死后细胞内的DNA和RNA含量推断死亡时间成为法医学的研究热点。     

死亡时间——当今中国法医病理学研究的热点及难点

在法医病理学研究的诸多重要问题中,时间问题无疑是其中的一个热点问题,同时也是一个难点问题。法医病理学中的时间问题主要包括:死亡时间、损伤时间、猝死者病理学标本能够诊断的时间(包括发病多久可以诊断及保存多久可以诊断)、水中经过时间等,其中尤其以死亡时间为研究热点。现结合本单位的研究结果,就死亡时间推断问题做一介绍。     

Developmental Validation of the Quantifiler® Duo DNA Quantification Kit for Simultaneous Quantification of Total Human and Human Male DNA and Detection of PCR Inhibitors in Biological Samples*

Abstract: The Quantifiler^® Duo DNA Quantification kit enables simultaneous quantification of human DNA and human male DNA as well as detection of inhibitors of PCR in a single real-time PCR well. Pooled human male genomic DNA is used to generate standard curves for both human (ribonuclease P RNA component H1) and human male (sex determining region Y) specific targets. A shift in the cycle threshold (C_T) values for the internal positive control monitors the presence of PCR inhibitors in a sample. The assay is human specific and exhibits a high dynamic range from 0.023 to 50 ng/μL. In addition, the multiplex assay can detect as little as 25 pg/μL of human male DNA in the presence of a 1000-fold excess of human female DNA. The multiplex assay provides assessment of the DNA extract and guidance for the selection of the appropriate AmpFℓSTR^® Amplification Kit to obtain interpretable short tandem repeat profiles.     

Implementation of a semi-automated processing system for DNA profiling of forensic casework samples

The concept for a semi-automated processing system for DNA analysis of crime scene samples was developed at the Landeskriminalamt Baden-Württemberg (LKA BW) and comprises the extraction of genomic DNA from human cells by ChargeSwitch^® magnetic bead technology (CST), quantification of purified DNA by real-time PCR, amplification of short tandem repeats (STRs) by PCR and DNA fragment length analysis of STRs by capillary electrophoresis. Three liquid handling workstations from Tecan, a real-time PCR device and a 16-channel capillary electrophoresis (CE) system, both from Applied Biosystems (AB), are linked via laboratory data network. Transmission and management of sample and analysis data is enabled by a Laboratory Information and Management System (LIMS). Suitability for a wide range of stain types, early exclusion of DNA-free samples, barcode sample identification and prevention of cross-contaminations guarantee efficiency and high quality standards.     

人脾脏细胞核DNA含量与死亡时间关系的图像分析

目的研究人脾脏细胞DNA含量改变与死亡时间的关系。方法选取36例已知死亡时间的人体脾脏,在死后5～36h内逐时进行细胞学涂片、Feulgen Vans染色观察,并用图像分析系统,测定脾脏细胞核积分光密度、平均灰度等灰度参数,所得数据用SPSS软件分析。结果在5～36h内平均光密度、积分光密度、平均灰度均值均与死亡时间显著性相关,并得出对应的回归方程,其中平均光密度、积分光密度随死亡时间的延长而逐渐减小、平均灰度逐渐增大。结论人脾脏细胞核DNA含量改变呈现一定规律,与死亡时间明显相关。     

Characterization of human DNA in environmental samples

Environmental samples from indoor surfaces can be confounded by dust, which is composed largely of human skin cells and has been documented to contain roughly tens of micrograms of total DNA per gram of dust. This study complements previous published work by providing estimates of the quantity of amplifiable human DNA found in environmental samples from a typical indoor environment, categorized by the intensity of human traffic and visible quantity of dust. Dust was collected by surface swabbing standard 576 cm² areas in eight locations, and evaluated for total DNA quantity, presence of human DNA (mitochondrial and nuclear loci using conventional PCR), quantity of human nuclear DNA using quantitative PCR, and STR analysis. The total DNA content of 36 dust samples ranged from 9 to 28 ng/cm², and contained 0.2–1.1 pg/cm² of human DNA. Overall, human DNA was detected in 97% of 36 dust samples and 61% of samples yielded allele distributions of varying degrees of complexity when subjected to STR analysis. The implications of this study are twofold. First, the presence of dust in evidence can be a significant contamination source in forensic investigations because the human DNA component is of sufficient quality and quantity to produce allele calls in STR analysis. This can be effectively managed by implementing stringent protocols for collection and analysis of potential biological samples. A second implication is the use of dust as a source of evidence for identification of inhabitants within a defined location. In the latter case, a number of additional studies would be necessary to identify relevant pretreatments for environmental dust samples and to develop the necessary deconvolution techniques to separate the composite genotypes obtained.     

试论亲子鉴定

什么是亲子鉴定?为什么需要做亲子鉴定?亲子鉴定提起的主体及几种情形,亲子鉴定的社会意义.亲子鉴定的是与非.由此而引起的争论.亲子鉴定在司法实践中作为证据使用时应该注意的问题.在社会转型时期人们信用的危机,婚姻家庭所面临的考验.