体外DNA扩增技术鉴定血痕性别三例报告

本文报道用体外DNA扩增技术对3例刑事案中的人血痕标本进行性别鉴定。其方法是从血痕标本中微量抽提DNA,用蛋白酶K进行消化。然后用两组引物Y1.1与Y1.2和Alu9.1与Alu9.2及国产FD耐热DNA聚合酶进行聚合酶链反(PCR)扩增DNA,电泳分析Y及Alu重复序列,从而判断血痕的性别。     

Evidence based strategy for normalization of quantitative PCR data,in forensic miRNA-analysis

Micro-RNA (miRNA) based analysis of body fluids and composition of complex crime stains has recently been introduced as a potential and powerful tool to forensic genetics. Analysis of miRNA analysis has several advantages over mRNA but reliable miRNA detection and quantification using quantitative PCR requires a solid and forensically relevant normalization strategy. In our study we evaluated a panel of 12 carefully selected reference genes for their suitability as endogenous controls in miRNA qPCR normalization in forensically relevant settings. We analyzed assay performances and variances in venous blood, semen, menstrual blood, saliva and vaginal secretion and mixtures thereof integrating highly standardized protocols with contemporary methodologies and included several well established computational algorithms.Based on these empirical results, we recommend normalization to the group of RNU24, RNU43, and RNU66, as this signature exhibits the most stable expression levels and the least expected variation among the evaluated candidate reference genes in forensically relevant body fluids. To account for the lack of consensus on how best to perform and interpret quantitative PCR experiments, our study's documentation is according to MIQE guidelines, defining the “minimum information for publication of quantitative real-time PCR experiments”.     

副溶血性弧菌LUXTM荧光PCR快速检测方法的建立

根据LUXTM荧光PCR技术原理,针对副溶血性弧菌toxR基因的保守序列,设计了特异的LUXTM荧光标记引物,通过优化反应条件与参数,建立了可快速检测副溶血性弧菌的LUXTM荧光PCR方法。结果显示,该方法高度敏感,对纯菌的检测低限达到每个反应体系7个菌(CFU),经6 h增菌培养后检测,对样品的检测低限(CFU)达到100/25 g;特异性强,对副溶血性弧菌2株标准菌株和10株参考菌株的检验均呈阳性,而对霍乱弧菌等28株非目标菌的检测均呈阴性;重复性好,定量检测的批内和批间变异系数均小于1%。应用此方法检测水产样品103份,检出阳性样品6份,与TaqMan荧光PCR和SN标准的检测结果完全一致。用此方法可在8 h内完成对样品中副溶血性弧菌的检测,其检测的快速性、敏感性和特异性与TaqMan荧光PCR技术相当,但检测成本更低。     

利用Y-STR特性侦破重大凶杀案1例

1简要案情河南某村庄发生一起重大凶杀案,村民赵某（女,32岁）及6岁女儿张某被人杀死在自己家里,母女俩人均被利器割断咽喉致死。经法医检验母女俩人无性侵犯,身上有明显搏斗痕迹。技术人员勘查现场后提取了现场血迹,赵某、张某血样及十指指甲,送检DNA检验。2 DNA检验及结果严格按照GA/T383-2002《法庭科学DNA检验规范》标准操作。（1）对现场血迹进行潜血试验及种属试验后确定全部为人血。     

大鼠皮肤和肌肉挫伤后细胞间黏附分子-1mRNA表达变化

目的应用实时荧光定量PCR技术检测大鼠皮肤和肌肉挫伤后组织中细胞间黏附分子－1（intercellular adhesion molecular－1，ICAM－1）mRNA的表达．分析其与损伤时间的关系。方法制备大鼠挫伤模型，于伤后0．5、l、6、12、18、24和30h取材，一步法提取总RNA，检测其完整性和质量浓度，逆转录合成第一链cDNA，以rpl32为内参基因进行荧光定量检测，采用△△Ct法比较其与正常皮肤、肌肉组织中ICAM－1mRNA表达的倍数关系。结果皮肤挫伤后ICAM－1mRNA的表达0．5h达到峰值，24h下降至正常对照组的7倍．随后再次升高：在肌肉组织中于损伤后0．5h表达显著增强，6h达到峰值，18h降至最低后再次升高。结论大鼠皮肤、肌肉挫伤后ICAM－1mRNA表达随损伤时间呈规律性变化，可望用于早期损伤时间推断。     

Application of less primer method to commercial kits

A modified PCR method is described. We examined the conditions of commercial kits including concentration of primer, amplification cycle number and annealing and extension time to obtain even PCR products as well accurate genotype analysis. In addition, we tried to arrange the ratio of primer composition in PowerPlex^® 16 system to improve the loci of high molecular and add two times of Taq Gold polymerase to decrease the extension time.The advantages of less primer method are good balance among loci, reproducibility and sensitivity.     

Performance of the SNPforID 52 SNP-plex assay in paternity testing

The performance of a multiplex assay with 52 autosomal single nucleotide polymorphisms (SNPs) developed for human identification was tested on 124 mother–child–father trios. The typical paternity indices (PIs) were 10⁵–10⁶ for the trios and 10³–10⁴ for the child–father duos. Using the SNP profiles from the randomly selected trios and 700 previously typed individuals, a total of 83,096 comparisons between mother, child and an unrelated man were performed. On average, 9–10 mismatches per comparison were detected. Four mismatches were genetic inconsistencies and 5–6 mismatches were opposite homozygosities. In only two of the 83,096 comparisons did an unrelated man match perfectly to a mother–child duo, and in both cases the PI of the true father was much higher than the PI of the unrelated man. The trios were also typed for 15 short tandem repeats (STRs) and seven variable number of tandem repeats (VNTRs). The typical PIs based on 15 STRs or seven VNTRs were 5–50 times higher than the typical PIs based on 52 SNPs. Six mutations in tandem repeats were detected among the randomly selected trios. In contrast, there was not found any mutations in the SNP loci. The results showed that the 52 SNP-plex assay is a very useful alternative to currently used methods in relationship testing. The usefulness of SNP markers with low mutation rates in paternity and immigration casework is discussed.     

鸡毒支原体鸡滑液囊支原体和副鸡禽杆菌三重PCR检测方法的建立

鸡毒支原体(MG)、鸡滑液囊支原体(MS)、副鸡禽杆菌(APG)三重PCR诊断对于鸡呼吸道疾病的鉴别诊断和防控有着重要意义。本次试验首先对三重PCR反应条件进行优化,之后对多种病原的DNA进行扩增以确定本方法的特异性,调整MG、MS和APG的DNA浓度以确定本方法的敏感性。结果显示,利用优化后的反应条件,本试验建立的诊断方法能够同时扩增出长度为453 bp(MG)、328 bp(MS)和241 bp(APG)的特异性片段,而大肠杆菌、鸡白痢沙门菌、禽多杀性巴氏杆菌、金黄色葡萄球菌和阴性对照样品在检测时则无条带产生。对三种病原的混合DNA进行10倍梯度稀释,确定MG、MS和APG的最低检出量为5×10^-3ng/μL。对37份临床样品的检测结果表明,三重PCR的检出率和单重PCR的检测结果一致,且可同时检测出两种或三种病原同时感染。上述结果表明,本试验建立的MG、MS和APG三重PCR诊断方法具有良好的特异性、较高的灵敏性,可用于鸡呼吸道病的诊断和防控。     

Multivariate analysis for estimating the age of a bloodstain

Our objective is to provide crime laboratories with a technique for estimating the age of a bloodstain. Toward that goal, we have used multiplexed, real-time RT-PCR (or qPCR) to determine the relative stability of different-sized segments of the same RNA species as well as differences in stability between two different RNAs' change over time in bloodstains. Our results indicate that a multivariate analysis of the changing ratio of the different RNA segments can be used to differentiate between samples of different ages in the defined population. Bloodstains from 29 of 30 donors could be partitioned into different ages using this technique. Although further improvements will be required before this approach can be implemented in crime laboratories, the multivariate analysis holds promise of providing a reliable approach for temporally linking a bloodstain to the commission of a crime or excluding a bloodstain as being irrelevant to the case in question.     

沂蒙黑山羊发情周期中输卵管促性腺激素受体基因的表达差异研究

采用RT-PCR方法,以持家基因GAPDH为内参,研究沂蒙黑山羊发情周期中卵泡刺激素受体(FSHR)mRNA和黄体生成素受体(LHR)mRNA在输卵管中的表达差异。结果表明,发情周期中促性腺激素受体mRNA在输卵管中都有表达。漏斗部FSHR mRNA在间情期的表达量最高,发情期表达量最低,且发情期与其他3个时期差异极显著(P<0.01)。壶腹部在间情期的表达量最高,发情前期表达量最低,间情期与其他时期差异极显著(P<0.01)。在峡部则是发情后期表达量最高,发情前期最低,发情前期与其他3个时期差异极显著(P<0.01)。LHR mRNA表达量与FSHR mRNA呈相反规律,以发情期漏斗部相对表达量最高,与其他部位差异极显著(P<0.01)。研究结果显示,发情周期中促性腺激素受体基因在输卵管中呈规律性的动态变化。表明,在动物排卵、受精及早期胚胎发育过程中促性腺激素受体mRNA起着一定的调节作用。