The use of Hemastix® severely reduces DNA recovery using the BioRobot® EZ1

Abstract: The choice of reagents for presumptive tests for blood, and subsequent extraction methodologies, can significantly affect both the quantity and quality of purified DNA. Blood samples directly tested with Hemastix^® yielded <1% of the DNA recovered from untested samples when purified using the Qiagen BioRobot^® EZ1 and EZ1^® DNA Investigator kit. Full short tandem repeat profiles were obtained from both tested and untested samples, suggesting that the Hemastix^® reagent(s) affect DNA binding, rather than produce DNA damage. The Hemastix^® inhibition of DNA yield could be overcome by the addition of MTL buffer to the sample prior to extraction. Laboratories may wish to modify current procedures for extracting blood samples, utilize other extraction/purification methodologies, or inform their submitting agencies to avoid direct exposure of questioned bloodstains to Hemastix^® reagents.     

CSF1PO,TPOX和TH01基因座复合扩增及其在苗族人群中的基因频率分布

在同一反应体系中，对CSFIPO，TPOX和TH01三个STR基因座做复合扩增，采用高分辨率的聚丙烯酸胺凝胶电泳分离、银染法显影技术，对云南苗族的3个基因座基因频率分布进行调查。CSFIPO基因座，观察到8个等位基因，17个基因型；TPOX基因座，观察到6个等位基因，14个基因型；TH01基因座，观察到6个等位基因，19个基因型。     

云南佤族、怒族和独龙族CTT基因座的遗传多态性

目的 了解云南佤族、怒族和独龙族等3个少数民族的CSF1PO、TPOX和THO1基因座遗传多态性分布。方法 应用3个基因座在同一反应体系中进行互不干扰的多重PCR,采用聚丙烯酰胺凝胶电泳分离、银染法显影技术,对云南3个少数民族的基因座进行遗传多态性调查。结果 获得了云南省佤族、怒族和独龙族3个基因座的基因频率分布资料。结论3个基因座基因频率分布与Hardy-Weinberg平衡吻合良好,在不同群体中发现一些有意义的遗传差异。     

A Study of PCR Inhibition Mechanisms Using Real Time PCR*,†

Abstract: In this project, real time polymerase chain reaction (PCR) was utilized to study the mechanism of PCR inhibition through examination of the effect of amplicon length, melting temperature, and sequence. Specifically designed primers with three different amplicon lengths and three different melting temperatures were used to target a single homozygous allele in the HUMTH01 locus. The effect on amplification efficiency for each primer pair was determined by adding different concentrations of various PCR inhibitors to the reaction mixture. The results show that a variety of inhibition mechanisms can occur during the PCR process depending on the type of co‐extracted inhibitor. These include Taq inhibition, DNA template binding, and effects on reaction efficiency. In addition, some inhibitors appear to affect the reaction in more than one manner. Overall we find that amplicon size and melting temperature are important in some inhibition mechanisms and not in others and the key issue in understanding PCR inhibition is determining the identity of the interfering substance.     

Genetic Data Analysis of Nine STRs in Two Caribbean Colombian Populations: César and Guajira

POPULATION:  We have analyzed the distribution of the allele frequencies and parameters of forensic interest at nine short tandem repeat (STR) loci (CSF1PO, D3S1358, D5S818, D7S820, D13S317, FGA, TH01, TPOX, and vWA) in a sample population of 165 unrelated individuals from César and Guajira, Caribbean populations of Colombia.     

江西汉族人群D2S1338、TPOX、TH01基因座多态性

本文采用Amp-FLP技术和银染法对D2S1338、TPOX、TH013个STR基因座遗传多态性进行了调查,现报道如下。1材料与方法1.1样本的采集及处理随机采集220人份江西地区汉族人群无血缘关系的个体静脉全血1m l,ACD抗凝。1.2 PCR扩增及产物的检测采用多位点STR同步扩增法,采用聚丙烯酰胺凝胶DNA电泳和银染法[1]。1.3统计学处理用χ2检验判断各位点的基因型分布是否符合Hardy-W einberg平衡法则,计算期望杂合度(H)、个体识别率(DP)和多态性信息含量(PIC值)[2]。2结果D2S1338共检出等位基因12个,基因频率分布在0.0023~0.1758之间;TPOX共…