DNA orientation during gel electrophoresis and its relation to electrophoretic mobility
DNA orientation during gel electrophoresis and its relation to electrophoretic mobility
复制标题
凝胶电泳过程中 DNA 方向及其与电泳迁移率的关系
作者：
I. Hurley
通过琼脂糖凝胶电泳，测定了与噬菌体λ DNA结合的乙硫醚的极化荧光强度。在电压梯度为8 V/cm时，DNA螺旋在电泳方向上的部分取向比在溶液中相同电场下所见的大500倍。Lumpkin等人[1985)生物聚合物，24,1573-1593]提出的凝胶电泳复制模型预测了这种取向。目前的结果可以成功地拟合这一理论与单一的可调参数，凝胶- dna的接触距离。同时，用相同的缓冲体系测定了相同浓度凝胶中λ DNA的电泳迁移率。在凝胶- DNA接触距离和DNA电荷与摩擦系数之比这两个参数相同的情况下，取向和迁移率的测量结果都可以在2倍的范围内符合重复理论。
Intensities of polarized fluorescence from ethidium bound to phage λ DNA undergoing agarose gel electrophoresis were measured. The intensities were strongly field dependent at voltage gradients of 8 V/cm, consistent with a partial orientation of DNA helices in the direction of electrophoresis about 500 times larger than seen in the same field in solution. Such an orientation was predicted by a reptation model of gel electrophoresis advanced by Lumpkin et al. [(1985) Biopolymers, 24, 1573–1593]. The present results can be fit successfully to this theory with a single adjustable parameter, the gel–DNA contact distance. Also, λ DNA electrophoretic mobilities in the same concentration gel were determined using the same buffer system. Both orientation and mobility measurements can be fit to the reptation theory within a factor of two using the same values of two parameters, the gel–DNA contact distance and the ratio of DNA charge to frictional coefficient.