Magnetic bead-based label-free electrochemical detection of DNA hybridization.
Magnetic bead-based label-free electrochemical detection of DNA hybridization.
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DOI：
10.1039/b106343j
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发表时间：
2001-11
期刊：
影响因子：
--
通讯作者：
J. Wang;A. Kawde;A. Erdem;M. Salazar
中科院分区：
文献类型：
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作者：
J. Wang;A. Kawde;A. Erdem;M. Salazar
磁珠捕获已用于消除非特异性吸附效应，这些效应阻碍了基于石墨电极上目标鸟嘌呤的剥离电位测量的 DNA 杂交的无标记检测。特别是，有效的磁分离对于区分不需要的成分非常有用，包括大量共存的错配和非互补寡聚体、染色体 DNA、RNA 和蛋白质。新方案涉及将生物素化寡核苷酸探针附着到链霉亲和素包被的磁珠上，然后进行杂交、DNA 杂交体从磁珠上解离，以及在可再生石墨铅笔电极上进行电位剥离测量。这种磁杂交表面与可再生石墨电极传感器和无标记电检测的耦合导致了大大简化的协议，并为集中和分散的基因测试提供了巨大的希望。还描述了一种新型磁性碳糊传感器，将溶液相磁分离与珠子捕获混合体的瞬时磁性收集相结合。下面说明了用于乳腺癌 BRCA1 基因相关 DNA 序列测定的基因磁无标记电实验方案的表征、优化和优势。
Magnetic bead capture has been used for eliminating non-specific adsorption effects hampering label-free detection of DNA hybridization based on stripping potentiometric measurements of the target guanine at graphite electrodes. In particular, the efficient magnetic separation has been extremely useful for discriminating against unwanted constituents, including a large excess of co-existing mismatched and non-complementary oligomers, chromosomal DNA, RNA and proteins. The new protocol involves the attachment of biotinylated oligonucleotide probes onto streptavidin-coated magnetic beads, followed by the hybridization event, dissociation of the DNA hybrid from the beads, and potentiometric stripping measurements at a renewable graphite pencil electrode. Such coupling of magnetic hybridization surfaces with renewable graphite electrode transducers and label-free electrical detection results in a greatly simplified protocol and offers great promise for centralized and decentralized genetic testing. A new magnetic carbon-paste transducer, combining the solution-phase magnetic separation with an instantaneous magnetic collection of the bead-captured hybrid, is also described. The characterization, optimization and advantages of the genomagnetic label-free electrical protocol are illustrated below for assays of DNA sequences related to the breast-cancer BRCA1 gene.