环介导等温扩增核酸技术及其在食品安全检测领域的应用

环介导等温扩增(Loop-mediated isothermal amplification,简称LAMP)是利用能识别靶序列上6个位点的4个特殊设计的引物和一种具有链置换活性的DNA聚合酶,在恒温条件下,特异、高效、快速地扩增核酸的新技术。该技术在1h内扩增效率可达到109-1010个数量级,扩增产物是一系列反向重复的靶序列构成的茎环结构和多环花椰菜样结构的DNA片段混合物,电泳后在凝胶上显现出由不同大小的区带组成的阶梯式图谱。近年来LAMP技术以其特异性强、等温灵敏、操作简单、产物易检测等优点已经应用于食品安全检测领域的多个方面。     

环介导的恒温扩增技术及其在病毒性疾病诊断中的应用

环介导的恒温扩增（LAMP）是近年来新兴的一种快速DNA扩增技术,其基本原理在于利用4个特殊设计的引物和具有链置换活性的DNA聚合酶,在恒温条件下对靶序列进行扩增。LAMP技术具有特异性强、敏感性高、反应迅速、设备简单等特点,在人类病毒性疾病的诊断领域有着广泛的应用。     

环介导等温扩增技术在临床上的应用

环介导等温扩增技术是一种在恒温条件下特异、高效、快速扩增DNA的新技术.不需要专业设备和人员,在一个反应体系中,通过四条特异性引物识别靶基因6个不同的位点,1h内完成整个扩增.扩增产物是一系列反向重复的靶序列构成的茎环结构和多环花椰菜样结构的DNA片段的混合物.通过肉眼观察浊度或加入荧光染料SYBR Green Ⅰ后的颜色变化即可判定结果.     

环介导等温扩增技术的应用进展

环介导等温扩增(loop-mediated isothermal amplification,LAMP)是一种新式核酸扩增技术,它依靠一种具有链置换活性的DNA聚合酶与2对特殊设计的引物,在等温条件下即可高效快速地完成扩增反应。相较于传统扩增检测方法,LAMP技术具有特异性强、灵敏度高、操作简单快速等优点,更能在现场快速检测和基层应用中广泛推广,目前LAMP技术已广泛应用于植物病害检测、动物病害检测、食品安全检测等领域。基于此,简要介绍了LAMP技术的基本原理、反应产物的检测方法,重点阐述了LAMP技术的改进与发展,综述了近年来其在科研生产中的应用进展,并对其发展前景进行了展望,以期为LAMP技术的进一步发展提供合理的研究方向。     

快速检测NDM-1基因的环介导恒温扩增技术的建立与评价

基于DNA环介导恒温扩增技术 (Loop-mediated isothermal amplification,LAMP),探索建立一种应用于NDM-1基因 (New Metallo-β-Lactamase-1 Gene,NDM-1) 的快速检测方法,以适应临床实验室等的检测需求。利用LAMP技术,以NDM-1基因为靶序列,设计4组LAMP引物,并筛选最优引物组,建立LAMP反应体系与条件,进行灵敏度和特异性实验。结果表明整个检测过程仅需1 h,即可通过肉眼直接目测实验结果。在灵敏度试验中,NDM-1基因的最低检测限为6 拷贝/反应。在特异性实验中,以4株病原菌 (肺炎克雷伯氏菌、大肠埃希氏菌、金黄色葡萄球菌、肺炎链球菌) 以及肠道菌群元基因组DNA、土壤菌群元基因组DNA为模板对NDM-1基因进行检测,结果显示均没有发生非特异性扩增反应。文中建立的LAMP检测方法能够快速检测NDM-1基因,且可直接观察到实验结果,实现了检测结果的可视化。具有操作简单安全、检测灵敏度高、特异性高的特点,能够满足基层实验室、应急检测或现场监测等方面的使用需求,具有良好的应用价值。     

多重环介导等温扩增技术的研究进展

环介导等温扩增技术(LAMP)是一种新型的核酸放大扩增技术。但是,当前的LAMP技术多是在同一个体系中对单一目标物进行检测,限制了其工作效率的发挥。多重LAMP技术就是在同一反应体系中加入多组针对不同靶基因的特异性引物,从而实现对多种目标基因同时进行扩增。我们针对多重LAMP的优缺点,对其在病毒、细菌、寄生虫以及性别筛选等领域的应用做简要综述。     

改良环介导等温扩增技术快速检测婴儿配方奶粉中的阪崎肠杆菌

[目的]采用改良环介导等温扩增(LAMP)技术,快速检测婴儿配方奶粉中的阪崎肠杆菌.[方法]以阪崎肠杆菌(ATCC29544)的16S-23S rRNA间区序列作为靶序列,设计内、外引物和环引物,通过肉眼观察白色沉淀,判断检测结果.[结果]LAMP检测阪崎肠杆菌的灵敏度为0.101 CFU/mL,人工污染阪崎肠杆菌的婴儿配方奶粉的检出限为1.1 CFU/g.采用试剂盒提取DNA,从样品处理到报告结果,耗时1 h.而对照,PCR检测阪崎肠杆菌的灵敏度为101 CFU/mL,人工污染阪崎肠杆菌的婴儿配方奶粉的检出限为1100 CFU/g.采用同样方法提取DNA,从样品处理到报告结果,耗时3 h.[结论]因此,LAMP检测婴儿配方奶粉中的阪崎肠杆菌灵敏度高,耗时短,方法简便.     

环介导等温扩增技术的常见问题分析与研究进展

环介导等温扩增(LAMP)技术是近年发展起来的新型核酸体外等温扩增技术,具有快速、特异、敏感、简便等特点,使该技术在核酸快速检测领域得到了广泛的应用,但LAMP技术也在不断完善与发展中。本文就LAMP扩增产物的污染,引物间非连续配对的假阳性问题的对策,以及在LAMP技术基础上发展起来的其他相关技术进行综述,为该技术在基层的推广应用提供参考。     

环介导等温扩增技术的研究进展

环介导等温扩增(loop-mediated isothermal amplification,LAMP)是一种新式核酸扩增技术,它依靠一种具有链置换活性的DNA聚合酶和2对特殊设计的引物,不需要反复的温度循环和昂贵的仪器设备,在等温条件下即可高效快速地完成扩增反应,目前已广泛应用于细菌、病毒、寄生虫等病原体的检测,及动物胚胎性别的鉴定。该文总结了LAMP技术的基本原理、相对于传统核酸检测技术的优点、产物的检测方法及其临床应用,最后指出LAMP目前存在的不足以及采取的相应措施,并对其发展前景进行了展望。     

水产品和水体中灿烂弧菌现场可视化环介导等温扩增快检方法的建立及应用

基于环介导等温扩增(LAMP)技术建立水产品和养殖水域中灿烂弧菌现场可视化的快速、简便检测方法.以灿烂弧菌等作为研究对象,以灿烂弧菌的toxR基因作为靶基因,确定煮沸法为适合于弧菌基因组DNA提取的快捷方法,优化筛选的引物可以特异地检测灿烂弧菌,检测核酸浓度的灵敏度可以达到10-9g/L,并且结果稳定、可靠.采用该方法...     

环介导等温基因扩增技术及其在病毒检测中的应用

环介导等温扩增是一门新兴的分子生物学检测技术,因其具有特异性高、敏感性高、简单、快捷及不需要昂贵的仪器设备等特点,受到了生物医学研究者的高度关注。目前,该方法已经被广泛应用于各种病原微生物检测。简要综述了环介导等温扩增技术的原理、特点,及其在病毒检测中的应用。     

Isolation of single-stranded DNA from loop-mediated isothermal amplification products.

Loop-mediated isothermal amplification (LAMP), in which a specific DNA sequence can be directly amplified under isothermal conditions, yields DNA in large quantities of more than 500 microg/ml. We have developed a method to isolate single-stranded DNA fragments from LAMP products that are stem-loop DNAs with several inverted repeats of the target DNA. This method requires the TspRI restriction enzyme, a primer hybridized to the 3' overhanging sequence at its cleavage site, and a DNA polymerase with strand displacement activity. The LAMP products are digested with TspRI and are then extended using the primer, producing the strand-specific DNA fragments. All processes, from LAMP reaction to primer extension, can be carried out at the same temperature. The use of strand-specific DNA would be conducive for detection by hybridization technique such as DNA microarrays.     

Detection of Bacillus anthracis from spores and cells by loop-mediated isothermal amplification without sample preparation

Loop-mediated isothermal amplification (LAMP) is a technique capable of rapidly amplifying specific nucleic acid sequences without specialized thermal cycling equipment. In addition, several detection methods that include dye fluorescence, gel electrophoresis, turbidity and colorimetric change, can be used to measure or otherwise detect target amplification. To date, publications have described the requirement for some form of sample nucleic acid extraction (boiling, lysis, DNA purification, etc.) prior to initiating a LAMP reaction. We demonstrate here, the first LAMP positive results obtained from vegetative cells and spores of Bacillus anthracis without nucleic acid extraction. Our data show that the simple addition of cells or spores to the reaction mixture, followed by heating at 63°C is all that is required to reproducibly amplify and detect target plasmid and chromosomal DNA via colorimetric change. The use of three primer sets targeting both plasmids and the chromosome of B. anthracis allows for the rapid discrimination of non-pathogenic bacteria from pathogenic bacteria within 30 min of sampling. Our results indicate that direct testing of B. anthracis spores and cells via LAMP assay will greatly simplify and shorten the detection process by eliminating nucleic acid purification. These results may allow more rapid detection of DNA from pathogenic organisms present in field and environmental samples.     

快速检测HBV DNA的环状介导等温DNA扩增法

环状介导等温DNA扩增（LAMP）技术是一种新的核酸扩增方法,它能够高特异性、高效、快速地进行核酸的扩增。利用LAMP法检测乙型肝炎病毒（HBV）,能够在等温条件下于1h内将少量的基因拷贝数扩增至10^9,在对65份临床标本的检测中显示了较高的特异性。与现有的PCR技术相比,LAMP法更加简便快速,且在等温条件下进行,不需要复杂的仪器设备,为临床检测乙肝病毒提供了一个快速筒便的新方法。     

Loop-mediated isothermal amplification (LAMP) of gene sequences and simple visual detection of products

As the human genome is decoded and its involvement in diseases is being revealed through postgenome research, increased adoption of genetic testing is expected. Critical to such testing methods is the ease of implementation and comprehensible presentation of amplification results. Loop-mediated isothermal amplification (LAMP) is a simple, rapid, specific and cost-effective nucleic acid amplification method when compared to PCR, nucleic acid sequence-based amplification, self-sustained sequence replication and strand displacement amplification. This protocol details an improved simple visual detection system for the results of the LAMP reaction. In LAMP, a large amount of DNA is synthesized, yielding a large pyrophosphate ion by-product. Pyrophosphate ion combines with divalent metallic ion to form an insoluble salt. Adding manganous ion and calcein, a fluorescent metal indicator, to the reaction solution allows a visualization of substantial alteration of the fluorescence during the one-step amplification reaction, which takes 30-60 min. As the signal recognition is highly sensitive, this system enables visual discrimination of results without costly specialized equipment. This detection method should be helpful in basic research on medicine and pharmacy, environmental hygiene, point-of-care testing and more.     

Detection of periodontal pathogen Porphyromonas gingivalis by loop-mediated isothermal amplification method

A method for nucleic acid amplification, loop-mediated isothermal amplification (LAMP) was employed to develop a rapid and simple detection system for periodontal pathogen, Porphyromonas gingivalis. A set of six primers was designed by targeting the 16S ribosomal RNA gene. By the detection system, target DNA was amplified and visualized on agarose gel within 30 min under isothermal condition at 64 degrees C with a detection limit of 20 cells of P. gingivalis. Without gel electrophoresis, the LAMP amplicon was directly visualized in the reaction tube by addition of SYBR Green I for a naked-eye inspection. The LAMP reaction was also assessed by white turbidity of magnesium pyrophosphate (a by-product of LAMP) in the tube. Detection limits of these naked-eye inspections were 20 cells and 200 cells, respectively. Although false-positive DNA amplification was observed from more than 10(7) cells of Porphyromonas endodontalis, no amplification was observed in other five related oral pathogens. Further, quantitative detection of P. gingivalis was accomplished by a real-time monitoring of the LAMP reaction using SYBR Green I with linearity over a range of 10(2)-10(6) cells. The real-time LAMP was then applied to clinical samples of dental plaque and demonstrated almost identical results to the conventional real-time PCR with an advantage of rapidity. These findings indicate the potential usefulness of LAMP for detecting and quantifying P. gingivalis, especially in its rapidity and simplicity.