A modified direct PCR amplification method using the GlobalFiler™ PCR Amplification Kit on bloodstains collected using microFLOQ™ direct swabs

The standard forensic DNA analysis workflow typically encompasses DNA extraction, quantification, STR-PCR amplification, and CE detection. A direct PCR amplification method eliminates the extraction and quantification steps, shortening the turnaround time for DNA profiling. However, a limitation to the direct PCR amplification method lies in its inability to allow for additional PCR amplification on the same sample. We found that replicate PCR amplifications can be afforded with the following modification to the direct PCR amplification method: after sample collection, the microFLOQ™ Direct swabs were incubated in low TE buffer prior to PCR amplification of the lysate. With replicate amplifications, the impact of stochastic effects during STR-PCR amplification on DNA profile interpretation would be reduced. Additionally, adjustments can be made to template volumes in subsequent amplifications, preventing oversaturated PCR reactions. Our results showed that this modified direct amplification method gave comparable median peak heights, allele recovery and intra-locus peak-height-ratio to those of the standard workflow, while maintaining the advantage of minimal evidence consumption.     

Detection and Identification of Psilocybe cubensis DNA Using a Real‐Time Polymerase Chain Reaction High Resolution Melt Assay,

Psilocybe cubensis, or “magic mushroom,” is the most common species of fungus with psychedelic characteristics. Two primer sets were designed to target Psilocybe DNA using web‐based software and NBCI gene sequences. DNA was extracted from eighteen samples, including twelve mushroom species, using the Qiagen DNeasy^® Plant Mini Kit. The DNA was amplified by the polymerase chain reaction (PCR) using the primers and a master mix containing either a SYBR^® Green I, Radiant? Green, or LCGreen Plus^® intercalating dye; amplicon size was determined using agarose gel electrophoresis. The PCR assays were tested for amplifiability, specificity, reproducibility, robustness, sensitivity, and multiplexing with primers that target marijuana. The observed high resolution melt (HRM) temperatures for primer sets 1 and 7 were 78.85 ± 0.31°C and 73.22 ± 0.61°C, respectively, using SYBR^® Green I dye and 81.67 ± 0.06°C and 76.04 ± 0.11°C, respectively, using Radiant? Green dye.     

荧光定量PCR技术研究线粒体DNA nt16519单核苷酸多态性

目的应用荧光定量PCR技术,建立mtDNA nt16519位点的PCR分型方法。方法应用Primer Express3．0软件,设计1对Taqman MGB探针和1埘扩增引物,在探针的5’端分别标记FAM和VIC报告荧光,应用7500荧光定量PCR和直接测序两种方法,分别榆测62份血样和18份毛发样本的mtDNA nt16519单核苷酸多态性,比较二种方法结果的一致性。结果62份血样和18份毛发样本均得到了可靠的mtDNA nt16519分型结果。结论建立的荧光定量PCR的分型方法操作简单、结果准确,适用于法医DNA检案。     

武汉汉族人群STR基因座D3S1358、D13S317、D12S391的多态性研究

目的　调查中国武汉地区汉族人群STR基因座—D3S1 358、D1 3S31 7、D1 2S391基因频率分布和群体遗传数据。方法　从 2 0 8个汉族无关个体收集血液标本 ,应用PCR技术及聚丙烯酰胺凝胶垂直板电泳对D3S1 358、D1 3S31 7和D1 2S391基因座分型。结果　D3S1 358检出 7个等位基因和 4 1个基因型。三基因座基因型分布符合Hardy-Weinberg平衡。观察 2 31次减数分裂均未发现突变基因。另外 ,调查结果计算显示D3S1 358、D1 3S31 7和D1 2S391基因座的杂合度 (H)分别为 0 70 98、 0 80 56和 0 84 0 0 ;三个人识别能力 (DP)分别为 0 851 6、 0 9332和 0 952 3;非父排除率 ( pE)分别为 0 4 463、 0 60 1 6和 0 681 8。结论　D3S1 358、D1 3S31 7和D1 2S391基因座在群体遗传学研究和法医学亲子鉴定及个人识别中具有较高实用价值     

反义RNA重组逆转录病毒逆转录套式PCR检测方法的建立

为探求一种快速检测反义RNA重组逆转录病毒效价的新方法,用脂质体介导法将反义RNA重组逆转录病毒载体pLXSA、pLXSB分别转染包装细胞系PA317,经G418筛选,获得数个稳定的产毒细胞克隆,择优挑选7个细胞克隆扩增培养,收集细胞上清,用异硫氰酸胍-酚一步法提取病毒RNA,进行逆转录套式PCR,检测细胞上清中的反义RNA重组逆转录病毒效价,同时用传统方法(小鼠成纤维放大法)进行测定。2种方法检测结果的比较表明,逆转录套式PCR法的特异性和敏感性均高于小鼠成纤维放大法,是一种敏感性高、特异性强、操作简便、快速的检测逆转录病毒效价的新方法。     

猪弓形虫病特异PCR诊断方法的建立

以核糖体DNA第一内转录间隔区(ITS1)序列作为弓形虫种特异的遗传标记,建立了猪弓形虫病特异PCR诊断方法。应用人工感染的方法建立了猪弓形虫病动物模型,摸索出猪弓形虫病PCR检测的最佳条件。敏感性和特异性试验结果显示,该PCR方法最低能检测到10 个弓形虫速殖子的DNA,且与相关的8种原虫和线虫均无交叉反应,证明该PCR方法具有高度的敏感性和特异性。动物感染试验结果证明,在试验猪出现明显临床症状时(感染后第5 d),对取材的8 个组织样品用该PCR方法检测,有6个组织样品为阳性,其中检出率最高的组织为肺门淋巴结。     

鸡传染性支气管炎北京地方株S_1基因的克隆与鉴定

利用反转录套式聚合酶链反应（ＲＴｎｅｓｔｅｄＰＣＲ）技术从北京地区３株鸡传染性支气管炎病毒（ＩＢＶ）分离株（ＢＪ１,ＢＪ２,ＢＪ３）中扩增出１０５４ｂｐＳ１基因高变区。利用限制性内切酶ＳｉｎⅠ和ＰｓｔⅠ的酶切位点分析图谱进一步证实了ＲＴｎｅｓｔｅｄＰＣＲ的特异性。将３段Ｓ１基因分别克隆到ｐＵＣ１９质粒中,获得重组质粒ｐＵＣＩＢＶＳ１ＢＪ１,ｐＵＣＩＢＶＳ１ＢＪ２和ｐＵＣＩＢＶＳ１ＢＪ３。     

Identification of a novel polymorphism in the X-chromosome region homologous to the DYS456 locus

During an extensive multipopulation study with Y-short tandem repeat (STR) loci, amplified using the AmpFlSTR Yfiler PCR amplification kit, amplification of a 71 bp fragment was observed in 2.32% of the male samples analyzed (N = 3141). By direct sequencing of this fragment, it was determined that the primer binding sequences were identical to those of the DYS456 locus. A T to G single-nucleotide polymorphism (SNP) enabled amplification of the 71 bp fragment. The SNP is located within an X-Y homologous region at Xq21.31 and was observed with the highest frequency within the African American and Sub-Saharan African populations in our study. Presence of SNP on the X chromosome did not interfere with the reliability of typing the DYS456 locus and the other Y-STR loci typeable using the AmpFlSTR Yfiler PCR amplification kit. Full profiles in a mixture of male:female at 1:4000 were obtained using the current configuration of the AmpFlSTR Yfiler kit even in the presence of female DNA containing the G variant.     

受污染烟蒂的DNA检验

采用chelex-100提取DNA并加以纯化,对受泥土等物严重污染的烟蒂中唾液上皮细胞DNA进行PCR扩增分型,成功地应用于案件检验,该方法方便,实用.     

猪支气管败血波氏杆菌PCR诊断方法的建立及应用

根据支气管败血波氏杆菌(Bordetella bronchiseptica)鞭毛蛋白基因的上游序列设计了1对引物fla1和fla2,扩增出大小为237 bp的目的基因片段,建立了快速检测支气管败血波氏杆菌的PCR方法。特异性和敏感性试验表明,该方法对大肠埃希氏菌、金黄色葡萄球菌和D型多杀性巴氏杆菌均无交叉性反应;最低能够检出112.5 pg的模板DNA。用该PCR法检测了从延边州采集的48份表现不同临床症状的猪鼻黏液;结果,检出支气管败血波氏杆菌阳性42例,阳性率为87.5%。同时与传统的细菌检查法、微量凝集法进行了比较;结果显示,该PCR法的检出率是细菌检查法的5.25倍,是微量凝集法的1.75倍。