Sizing DNA using a nanometer-diameter pore
Sizing DNA using a nanometer-diameter pore
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DOI：
10.1529/biophysj.104.041814
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发表时间：
2004-10-01
影响因子：
3.4
通讯作者：
Timp, G
中科院分区：
文献类型：
--
作者：
Heng, JB;Ho, C;Timp, G
从细菌到人类的每一个物种都有一个独特的遗传指纹。因此，检测单个DNA分子的机制代表了最终的分析工具。作为开发这种工具的第一步，我们探索了使用纳米直径的孔，用紧密聚焦的电子束溅射在纳米厚的无机膜上，作为检测DNA单分子并产生结构的电子签名的换能器。当跨膜施加电场时，浸没在电解质中的DNA分子被吸引到孔，阻断通过它的电流，并最终跨膜易位，如通过凝胶电泳明确验证的。通过分子动力学模拟，建立了DNA易位与阻断电流之间的关系。通过测量阻断电流瞬变的持续时间和幅度，我们可以区分单链和双链DNA，并解析聚合物的长度。
Each species from bacteria to human has a distinct genetic fingerprint. Therefore, a mechanism that detects a single molecule of DNA represents the ultimate analytical tool. As a first step in the development of such a tool, we have explored using a nanometer-diameter pore, sputtered in a nanometer-thick inorganic membrane with a tightly focused electron beam, as a transducer that detects single molecules of DNA and produces an electrical signature of the structure. When an electric field is applied across the membrane, a DNA molecule immersed in electrolyte is attracted to the pore, blocks the current through it, and eventually translocates across the membrane as verified unequivocally by gel electrophoresis. The relationship between DNA translocation and blocking current has been established through molecular dynamics simulations. By measuring the duration and magnitude of the blocking current transient, we can discriminate single-stranded from double-stranded DNA and resolve the length of the polymer.