中文摘要：本文用等温比色法对转基因生物中的CaMV 35S启动子序列进行扩增检测。该方法基于（a）靶DNA触发的未标记分子信标（UMB）的末端结合、（b）核酸外切酶III（Exo III）辅助的靶循环、（c）G-四链体/血红素DNA酶扩增。研究发现，该方法能够在低至0.23 nm的浓度下灵敏地测定转基因生物的 DNA；利用等温培养的优点，该方法不需要复杂的设备或复杂的合成；分析过程可以在90分钟内完成；该方法还可鉴别单碱基错配。研究结果表明，该方法可用于许多其他转基因生物的检测。
 
外文摘要：An isothermal colorimetric method is described for amplified detection of the CaMV 35S promoter sequence in genetically modified organism (GMO). It is based on (a) target DNA-triggered unlabeled molecular beacon (UMB) termini binding, and (b) exonuclease III (Exo III)-assisted target recycling, and (c) hemin/G-quadruplex (DNAzyme) based signal amplification. The specific binding of target to the G-quadruplex sequence-locked UMB triggers the digestion of Exo III. This, in turn, releases an active G-quadruplex segment and target DNA for successive hybridization and cleavage. The Exo III impellent recycling of targets produces numerous G-quadruplex sequences. These further associate with hemin to form DNAzymes and hence will catalyze H2O2-mediated oxidation of the chromogenic enzyme substrate ABTS(2-) causing the formation of a green colored product. This finding enables a sensitive colorimetric determination of GMO DNA (at an analytical wavelength of 420 nm) at concentrations as low as 0.23 nM. By taking advantage of isothermal incubation, this method does not require sophisticated equipment or complicated syntheses. Analyses can be performed within 90 min. The method also discriminates single base mismatches. In our perception, it has a wide scope in that it may be applied to the detection of many other GMOs.
外文关键词：GMO, CaMV 35S, DNA detection, Isothermal amplification, Molecular beacon, Oligonucleotide, Absorption intensity, Microplate photometer, Biosensor
作者：Zhang, Decai; Wang, Weijia; Dong, Qian; Huang, Yunxiu; Wen, Dongmei; Mu, Yuejing; Yuan, Yong
作者单位：Sun Yat Sen Univ
期刊名称：MICROCHIMICA ACTA
期刊影响因子：5.705
出版年份：2018
出版刊次：1
点击下载：基于核酸外切酶Ⅲ辅助靶循环和G-四链体/血红素DNA酶扩增的转基因生物比色检测研究