Theory of DNA electrophoresis in physical gels and entangled polymer solutions.
Theory of DNA electrophoresis in physical gels and entangled polymer solutions.
复制标题
物理凝胶和缠结聚合物溶液中的 DNA 电泳理论。
DOI：
--
复制
发表时间：
1994
期刊：
影响因子：
--
通讯作者：
Viovy
中科院分区：
文献类型：
--
作者：
Duke;Viovy
提出了DNA在筛分介质（如物理凝胶和纠缠聚合物溶液）中形成动态演化网络的电泳迁移率的标度理论。在这种介质中，DNA运动的拓扑约束随着交联断裂和重新连接或聚合物扩散而不断变化。结果表明，如果约束释放速率在一定范围内（取决于场强），分馏可以扩展到比使用等效孔径的永久凝胶更大的分子量。这种改进是约束释放对分子取向机制的破坏性作用的结果。数值模拟支持了该理论的预测。以改进现有的电泳方法为目的，对该系统在实际应用中实现的可能性进行了评述。这表明，半稀聚合物溶液可能是快速分离长单链DNA分子的通用介质，并确定了所需溶液的特定质量。
A scaling theory is presented for the electrophoretic mobility of DNA in sieving media that form dynamically evolving meshworks, such as physical gels and solutions of entangled polymers. In such media, the topological constraints on the DNA's motion are perpetually changing as cross links break and rejoin or as the polymers diffuse. It is shown that if the rate of constraint release falls within a certain range (which depends on the field strength), fractionation can be extended to higher molecular weights than would be feasible using a permanent gel of equivalent pore size. This improvement is a consequence of the disruptive effect that constraint release has on the mechanism of molecular orientation. Numerical simulations support the predictions of the theory. The possibility of realizing such a system in practice, with the aim of improving on current electrophoresis methods, is commented upon. It is suggested that semidilute polymer solutions may be a versatile medium for the rapid separation of long single-stranded DNA molecules, and the particular quality of solution required is identified.