大肠杆菌质粒的快速提取

质粒的提取是生物学中的常规技术之一 ,但常规法提取质粒十分复杂 ,繁琐并且费时。国外公司的试剂盒大大简化了此过程。但价格使国内大多数实验室难以承受。我们利用自制的玻璃粉提取质粒 ,大大简化了提取过程 ,同时相对于进口试剂盒而言 ,实验成本也大大降低     

定点突变三种方法的比较研究

目的：通过使用优化后的定点突变三种方法分别对一个新基因重组载体进行定点突变研究,比较这几种定点突变方法的优缺点。方法：重叠延伸PCR法使用Stratagene在线定点突变引物设计程序从而使引物设计简化而可靠;MutaBEST定点突变试剂盒采用胶纯化试剂盒代替说明书推荐的酚-氯仿抽提质粒的方法以提高回收率;使用PrimeSTAR高保真DNA聚合酶和超级感受态试剂盒代替Quikchange定点突变试剂盒的相应组分可使产物不受影响同时降低试验费用。结果：三种方法都能够获得单碱基突变重组载体。结论：QuikChange突变策略通过改进是一种高效、简洁、经济和可靠的定点突变方法。     

黄曲霉毒素B_1抗独特型抗体的制备和应用研究II.抗独特型抗体应用

以抗独特型抗体(anti-idiotypeantibody,Ab2)的酶切片段Fab2替代黄曲霉毒素B1(AFB1)建立一种不需要使用AFB1的无毒酶联免疫吸附(Enzyme-LinkedImmunosorbentAssay,ELISA)试剂盒,研究该试剂盒特异性、稳定性和AFB1的加标回收,并将该试剂盒用于农产品和饲料中AFB1的检测。结果表明,该试剂盒具有和常规ELISA试剂盒一样的特异性和加标回收能力,无毒试剂盒和常规试剂盒一样都可以用于农产品和饲料中AFB1的检测,并且两种试剂盒的检测结果并无显著差异,无毒ELISA试剂盒在适当处理后,40C放置3个月和-200C放置5个月,以间接非竞争ELISA测定的吸光值分别是起始时的85%和87%。     

Beacon公司微囊藻毒素检测试剂盒的性能评价

对一种进口微囊藻毒素ELISA试剂盒进行应用性能评价。用该试剂盒进行精密度实验,标准品添加回收实验,交叉反应实验以及样品检测比较实验。试剂盒的分析内检测精密度较高,分析间检测精密度偏低,加标回收率在73.5-97.8%之间,试剂盒抗体与MC-LR的交叉反应率很高,但与MC-RR、MC-LW、MC-LF等微囊藻毒素异构体交叉反应率偏低,在水样的测定中,试剂盒检测结果与本实验室方法检测结果基本一致。该试剂盒基本能够满足对水体中MC-LR的定性和定量检测要求。     

黄曲霉毒素B1抗独特型抗体的制备和应用研究II.抗独特型抗体应用

以抗独特型抗体(anti-idiotypeantibody,Ab2)的酶切片段Fab2替代黄曲霉毒素B1(AFB1)建立一种不需要使用AFB1的无毒酶联免疫吸附(Enzyme-LinkedImmunosorbentAssay,ELISA)试剂盒,研究该试剂盒特异性、稳定性和AFB1的加标回收,并将该试剂盒用于农产品和饲料中AFB1的检测。结果表明,该试剂盒具有和常规ELISA试剂盒一样的特异性和加标回收能力,无毒试剂盒和常规试剂盒一样都可以用于农产品和饲料中AFB1的检测,并且两种试剂盒的检测结果并无显著差异,无毒ELISA试剂盒在适当处理后,40C放置3个月和-200C放置5个月,以间接非竞争ELISA测定的吸光值分别是起始时的85%和87%。     

食源性致病菌核酸标准物质的研究进展

核酸检测试剂盒在微生物快速检测领域飞速发展,使检测过程具有操作简单、成本低、便于现场检测的优势,食源性致病菌核酸检测试剂盒在制备过程中需要通过计量溯源以确保其定性及定量的测量能力。核酸标准物质（nucleic acid reference materials,NARMs）应用于临床卫生、食品、仪器检定/校准以及核酸检测等多个领域,通过片段化分割遗传物质,最大程度地保障生物安全性,满足质量评价和计量溯源的需求,能够对核酸检测试剂盒进行有效质控,为核酸检测试剂盒的量值评价提供精准的“标尺”。综述了我国NARMs的研制方法,重点阐述了目前食源性致病菌的研究现状以及在国家标准物质资源共享平台的应用情况,分析了面临的技术挑战以及未来核酸计量工作发展的可能性,以期为核酸检测行业的早期诊断和防控提供参考。     

黄曲霉毒素B1抗独特型抗体的制备和应用研究Ⅱ.抗独特型抗体应用

以抗独特型抗体(anti-idiotype antibody,Ab2)的酶切片段Fab2替代黄曲霉毒素B1(AFB1)建立一种不需要使用AFB1的无毒酶联免疫吸附(Enzyme-Linked Immunosorbent Assay,ELISA)试剂盒,研究该试剂盒特异性、稳定性和AFB,的加标回收,并将该试剂盒用于农产品和饲料中AFB1的检测。结果表明,该试剂盒具有和常规ELISA试剂盒一样的特异性和加标回收能力,无毒试剂盒和常规试剂盒一样都可以用于农产品和饲料中AFB1的检测,并且两种试剂盒的检测结果并无显著差异,无毒ELISA试剂盒在适当处理后,4℃放置3个月和-20℃放置5个月,以间接非竞争ELISA测定的吸光值分别是起始时的85％和87％。     

安捷伦科技推出微阵列芯片新品

<正>安捷伦科技公司近日推出了一款高通量寡核苷酸微阵列芯片——GenetiSure预筛选试剂盒,该款产品应用于筛选第三天和第五天胚胎中单细胞中的非整倍体以及其他5~10 Mb范围内的基因组畸变。该款试剂盒可将从DNA提取到数据分析之间的运行时间缩短至八小时以内。此外,该款试剂盒包含的微阵列芯片可同时分析多达     

呼吸道合胞病毒IgG酶联检测试剂盒的研制

为了研制检测呼吸道合胞病毒IgG的酶联检测试剂盒,以呼吸道合胞病毒Long株病毒液作为包被抗原,HRP标记羊抗人IgG作为信号抗体,制备ELISA抗体检测试剂盒。结果表明建立的RSV酶联检测试剂盒敏感性与进口试剂盒接近,特异性达 95. 24%,重复性好,批内变异系数为 6. 35%,试剂盒置于 37℃ 0天与 7天检测结果无显著差异。成功制备了RSVIgG酶联检测试剂盒。     

Ⅱ型猪圆环病毒PCR检测方法的建立及试剂盒的研制

根据Cenbank上已发表的Ⅱ型猪圆环病毒（PCV-2）的基因序列,设计并合成一对能特异性扩增Ⅱ型猪圆环病毒的引物,通过对PCR方法的优化,建立了PCR方法检测PCV-2并研制出试剂盒。然后对试剂盒的敏感性、特异性和有效期进行了研究。结果表明,该试剂盒具有很好的特异性和敏感性,有效期在-20℃至少可以保存一年。     

Optimization of a high-throughput CTAB-based protocol for the extraction of qPCR-grade DNA from rumen fluid, plant and bacterial pure cultures

The quality and yield of extracted DNA are critical for the majority of downstream applications in molecular biology. Moreover, molecular techniques such as quantitative real-time PCR (qPCR) are becoming increasingly widespread; thus, validation and cross-laboratory comparison of data require standardization of upstream experimental procedures. DNA extraction methods depend on the type and size of starting material(s) used. As such, the extraction of template DNA is arguably the most significant variable when cross-comparing data from different laboratories. Here, we describe a reliable, inexpensive and rapid method of DNA purification that is equally applicable to small or large scale or high-throughput purification of DNA. The protocol relies on a CTAB-based buffer for cell lysis and further purification of DNA with phenol : chloroform : isoamyl alcohol. The protocol has been used successfully for DNA purification from rumen fluid and plant cells. Moreover, after slight alterations, the same protocol was used for large-scale extraction of DNA from pure cultures of Gram-positive and Gram-negative bacteria. The yield of the DNA obtained with this method exceeded that from the same samples using commercial kits, and the quality was confirmed by successful qPCR applications.     

以川陕哲罗鲑为目标物种的水样环境DNA分析流程的优化

水样环境DNA分析包括水样采集、DNA提取和分析等流程,已成为监测濒危水生生物种群分布调查的重要手段.为减少在监测目标物种尤其濒危物种中的不确定性,对水环境DNA分析流程的优化至关重要.本研究以川陕哲罗鲑为目标物种,采用滤膜法采集养殖池中的水样,设计了 250 mL、500 mL、1 L和2 L等4种水样采集量,分别采用 PoweWater DNA Isolation kit和DNeasy Tissue and Blood DNA extraction kit 提取水样环境DNA(eDNA),使用物种mtDNA D_loop区特异性引物进行PCR扩增,通过研究滤膜法、水样采集量和水样DNA提取方法对水样eDNA中目标基因检出率的影响,探索适宜的eDNA分析操作方案.结果表明: 使用DNeasy Tissue and Blood DNA extraction kit提取的水样DNA中目的基因的检出率为100%,效果明显优于PoweWater DNA Isolation kit(目标基因的检出率为0);目标基因扩增条带的亮度随水样采样量的增加而增加,其中2 L水样目标基因的扩增效果较理想;序列比对结果显示,本试验从水样DNA中成功扩增得到了川陕哲罗鲑mtDNA Dloop区部分序列.表明DNA提取方法和水样采集量对目标物种的检出率有显著的影响,滤膜法、2 L水样采集量、DNeasy Tissue and Blood DNA extraction kit更适宜进行水样的DNA分析,mtDNA D-loop区可作为川陕哲罗鲑识别的特异性分子标记.     

鱼肝线粒体DNA的简易提纯方法

本文报道一种简易分离纯化线粒体DNA(mtDNA)的方法。即以差速离心或蔗糖梯度离心制得线粒体后,用RNase除去RNA,可得纯mtDNA,或用凝胶过滤、或低熔点琼脂糖法纯化之。所获纯mtDNA可用于限制性酶切图谱的组建和其片段的克隆。此法可避开冗长的昂贵的超速离心,故可为普通实验室所采用。文中还讨论了mtDNA纯化和得率的因素。     

Establishment of a semi-automated pathogen DNA isolation from whole blood and comparison with commercially available kits

Molecular methods for bacterial pathogen identification are gaining increased importance in routine clinical diagnostic laboratories. Achieving reliable results using DNA based technologies is strongly dependent on pre-analytical processes including isolation of target cells and their DNA of high quality and purity. In this study a fast and semi-automated method was established for bacterial DNA isolation from whole blood samples and compared to different commercially available kits: Looxster, MolYsis kit, SeptiFast DNA isolation method and standard EasyMAG protocol. The newly established, semi-automated method utilises the EasyMAG device combined with pre-processing steps comprising human cell lysis, centrifugation and bacterial pellet resuspension. Quality of DNA was assessed by a universal PCR targeting the 16S rRNA gene and subsequent microarray hybridisation. The DNA extractions were amplified using two different PCR-mastermixes, to allow comparison of a commercial mastermix with a guaranteed bacterial DNA free PCR mastermix. The modified semi-automated EasyMAG protocol and the Looxster kit gave the most sensitive results. After hybridisation a detection limit of 10¹ to 10² bacterial cells per mL whole blood was achieved depending on the isolation method and microbial species lysed. Human DNA present in the isolated DNA suspension did not interfere with PCR and did not lead to non-specific hybridisation events.     

两种外周血 DNA 提取方法的比较

目的:外周血DNA的提取是研究乙型肝炎病毒相关临床疾病的基础,所提取DNA的质与量直接关乎下游研究的成败,经济、高效、便捷的外周血DNA提取方法对于疾病分子水平的研究尤为重要,本实验旨在比较两种外周血DNA提取方法,从而为临床研究提供有力的参考。方法:以外周抗凝血为试验样本,分别采用改良盐析法和DNA提取试剂盒法(硅胶柱纯化)进行基因组DNA的提取,通过分光光度仪测量DNA浓度和纯度,并进行PCR扩增及电泳实验。比较改良盐析法与试剂盒提取法(硅胶柱纯化)的效果。结果:试剂盒提取法(硅胶柱纯化)标本用量甚微,省时,提取DNA纯度高,步骤繁琐,PCR条带单一、亮度差;改良盐析法操作步骤少,提取DNA浓度高,PCR条带亮度佳、杂带多,耗时长。结论:两组方法各有优缺点,试剂盒提取法(硅胶柱纯化)可靠、快速,但所获DNA量少、极易降解,改良盐析法耗时,但所获DNA浓度高、量多,可根据实验时间与经费,实验所需的DNA纯度与浓度,提供的样本体积等不同的临床研究需求及条件来综合选择适宜的提取方法。     

Ready-to-use DNA extracted with a CTAB method adapted for herbarium specimens and mucilaginous plant tissue

This report summarizes major changes in previously published protocols for DNA extraction to improve the quality of DNA extracted from plants. Here, we highlight the critical modifications in the original protocols. The efficiency of these changes results in high-quality DNA ready to use in a variety of phytogenetically distant plant families, in particular species with mucopolysaccharides. The DNA obtained can be used without further purification in various molecular biology assays, including direct sequencing and AFLP and RAPD (random-amplified polymorphic DNA) analyses. The effectiveness of this method is proven by the amplification and sequencing of PCR products of up to 1 kb with DNA extracted from herbarium tissue ≥60 years old. This versatility is not usually found in DNA extraction protocols. In addition, this method is quick, adaptable to standard laboratories, and most important, safer and more cost-effective.     

Comparison of five commercial DNA extraction kits for the recovery of Yersinia pestis DNA from bacterial suspensions and spiked environmental samples

Aim:  To evaluate commercial DNA extraction kits for their ability to isolate DNA from Yersinia pestis suspensions and spiked environmental samples.
Methods and Results:  Five commercially available DNA extraction kits were evaluated: the ChargeSwitch gDNA Mini Bacteria Kit, the IT 1-2-3 Sample DNA Purification Kit, the MasterPure Complete DNA and RNA Purification Kit, the QIAamp DNA Blood Mini Kit and the UltraClean Microbial DNA Isolation Kit. The extraction methods were performed upon six Y. pestis strains and spiked environmental specimens, including three swab types and one powder type. Taqman real-time PCR analysis revealed that the use of the MasterPure kit resulted in DNA with the most consistently positive results and the lowest limit of detection from Y. pestis suspensions and spiked environmental samples.
Conclusion:  Comparative evaluations of the five commercial DNA extraction methods indicated that the MasterPure kit was superior for the isolation of PCR-amplifiable DNA from Y. pestis suspensions and spiked environmental samples.
Significance and Impact of the Study:  The results of this study can assist diagnostic laboratories with selecting the best extraction method for processing environmental specimens for subsequent detection of Y. pestis by real-time PCR.     

Comparison of DNA extraction from cervical cells collected in PreservCyt solution for the amplification of Chlamydia trachomatis

OBJECTIVE: The aim of this study was to compare and evaluate three methods of DNA extraction for the amplification of Chlamydia trachomatis in uterine cervical samples collected in PreservCyt solution. ThinPrep is the trade name for the slide preparation. METHODS: Thirty-eight samples collected in LCx buffer medium, which were identified as C. trachomatis infected by ligase chain reaction (LCR), were selected for this study. DNA from the PreservCyt samples was extracted by three methods: (i) QIAamp kit, (ii) boiling in Tris-EDTA buffer with Chelex purification, and (iii) Proteinase K digestion with Chelex purification. Sample DNA was tested for the presence of C. trachomatis by PCR using cryptic plasmid research (CTP) primers and major outer membrane protein research momp gene (MOMP) primers. Real-time (LightCycler) PCR for relative C. trachomatis quantification following DNA extraction was performed using primers (Hsp 60) for the 60 kDa heat-shock protein hsp60 gene. RESULTS: Amplification using CTP primers was the most successful with each of the extraction protocols. Boiling in buffer was the least successful extraction method. QIAamp was the best extraction method, yielding the most positives with both the CTP and MOMP primers. Proteinase K-Chelex extraction gave similar sensitivity to QIAamp extraction with CTP primers but lower for MOMP primers. CONCLUSIONS: The DNA extraction method must be carefully selected to ensure that larger PCR amplicons can be successfully produced by PCR and to ensure high sensitivity of detection of C. trachomatis. In this study it was found that the QIAamp extraction method followed by PCR with the CTP primers was the most successful for amplification of C. trachomatis DNA.     

四种土壤微生物总DNA的纯化方法的比较

比较了4种从土壤中直接抽提的微生物总DNA的纯化方法,实验结果表明1 %的琼脂糖凝胶电泳纯化方法及葡聚糖凝胶G 2 0 0离心层析纯化方法均不能完全纯化从土壤中抽提的微生物总DNA。若将直接抽提的总DNA先经葡聚糖凝胶G 2 0 0离心层析纯化,再用1 %的琼脂糖凝胶电泳纯化,则能取得较好的纯化效果。含2 %PVP的1 %琼脂糖凝胶电泳纯化,用DNA凝胶回收试剂盒回收后没有得到纯化后的土壤微生物总DNA。     

Overexpression and rapid purification of Escherichia coli formamidopyrimidine-DNA glycosylase

Formamidopyrimidine DNA glycosylase (Fpg) is a DNA glycosylase with an associated AP lyase activity. As a DNA repair enzyme, Fpg excises several modified bases from DNA associated with exposure to oxidizing agents such as free radicals. Experiments in many laboratories have been limited by the availability of the enzyme, and its production required at least a week of work to complete its purification. We have devised a new method that decreases the time and expense of purification of Fpg that should render this protein accessible to any laboratory. Fpg was subcloned into a gamma P(L) promoter-containing vector (pRE) and overproduced in the appropriate Escherichia coli host cells to about 25% of the total cellular protein. Fpg was purified to homogeneity in a simple two-step procedure with a 50% saving in time when compared to the previously known procedure. Comparative studies showed that the excision of 8-hydroxyguanine, 2,6-diamino-4-hydroxy-5-formamidopyrimidine, and 4,6-diamino-5-formamidopyrimidine, and to a lesser extent, 8-hydroxyadenine was virtually identical for the Fpg purified using this method and for the Fpg purified by the original method. Therefore, this method should prove useful for a large number of laboratories and further research on oxidative DNA damage.