Slater G W, Guo H L
Department of Physics, University of Ottawa, Ontario, Canada.
Electrophoresis. 1996 Sep;17(9):1407-15. doi: 10.1002/elps.1150170903.
Recently, we developed a lattice model to study the dynamics of particles being electrophoresed in gels (G. W. Slater, H. L. Guo, Electrophoresis 1995, 16, 11-15). In Part I of this series (G. W. Slater, H. L. Guo, Electrophoresis 1996, 17,977-988), we showed how to calculate the exact electrophoretic mobility of one-site particles in the limit where the electric field intensity E is vanishingly small. Since we can solve the model for arbitrary gel structures in two or more dimensions, we compared our results with those of the Ogston-Morris-Rodbard-Chrambach model (OMRCM) of gel electrophoresis, which assumes that the mobility (mu) of charged particles is directly proportional to the fractional gel volume (f) that is available to them. Our results and theoretical analysis indicated that the OMRCM is a mean-field approximation that can be useful as a rough guide; however, it generally misses the subtle sieving effects related to the correlations between the position of the obstacles in a given gel structure. In this paper (Part II) we study, for two-dimensional periodic gels, the exact relationships between the zero-field mobility mu and the gel concentration C for larger particle sizes. The fact that mu is a strong function of the particle size suggests that we can separate large particles using two-dimensional periodic gels (similar to those fabricated by W.D. Volkmuth and R.H. Austin, Nature 1992, 358, 600-602). We analyze our data using Ferguson-like plots and we show that one can indeed use a generalized retardation coefficient, K, to estimate the effective pore size aK and effective fiber size rK for these model gels. We conclude that the retardation coefficient is a useful concept to characterize a sieving structure even though it does not permit the inference of the exact gel structure.
最近，我们开发了一种晶格模型来研究在凝胶中进行电泳的粒子的动力学（G. W. 斯莱特，H. L. 郭，《电泳》1995年，第16卷，第11 - 15页）。在本系列的第一部分（G. W. 斯莱特，H. L. 郭，《电泳》1996年，第17卷，第977 - 988页）中，我们展示了如何在电场强度E趋近于零的极限情况下计算单点粒子的精确电泳迁移率。由于我们可以求解二维或更多维任意凝胶结构的模型，我们将我们的结果与凝胶电泳的奥格斯顿 - 莫里斯 - 罗德巴德 - 克兰巴赫模型（OMRCM）的结果进行了比较，该模型假设带电粒子的迁移率（μ）与它们可利用的凝胶体积分数（f）成正比。我们的结果和理论分析表明，OMRCM是一种平均场近似，可作为一个大致的指导；然而，它通常忽略了与给定凝胶结构中障碍物位置之间的相关性相关的细微筛分效应。在本文（第二部分）中，我们研究了二维周期性凝胶中，对于较大粒径的零场迁移率μ与凝胶浓度C之间的精确关系。μ是粒径的强函数这一事实表明，我们可以使用二维周期性凝胶（类似于W.D. 沃尔克穆特和R.H. 奥斯汀制作的那些，《自然》1992年，第358卷，第600 - 602页）来分离大粒子。我们使用类似弗格森图的方法分析我们的数据，并且我们表明，对于这些模型凝胶，确实可以使用广义延迟系数K来估计有效孔径aK和有效纤维尺寸rK。我们得出结论，延迟系数是表征筛分结构的一个有用概念，尽管它不允许推断出精确的凝胶结构。
