Stigter D
Department of Pharmaceutical Chemistry, University of California, San Francisco 94143.
Cell Biophys. 1987 Dec;11:139-58. doi: 10.1007/BF02797120.
This is a review of applications of the McMillan-Mayer-Hill virial theory and the ionic double-layer theory to dilute colloidal solutions, in particular, solutions of DNA. Interactions of highly charged colloidal rods are developed in terms of the second virial coefficients between two rods, and between one rod and one small co-ion. The relevant cluster integrals are evaluated with interaction potentials based on the Poisson-Boltzmann equation. The treatment is extended to the intrachain repulsion responsible for the statistical swelling of coiled DNA (excluded volume effect). The theory is compared with three sets of experimental data: The salt distribution in Donnan membrane equilibria of DNA-salt solutions, sedimentation equilibria of short DNA fragments at different ionic strengths, and the intrinsic viscosity of T7 DNA in NaCl solutions. In all cases the theory agrees well with the experiments. The agreement is not convincing for the sedimentation equilibrium at low ionic strength, because here the experimental DNA concentration is too high for the truncated dilute solution expansion of the DNA-salt repulsion.
本文综述了麦克米兰-迈耶-希尔维里理论和离子双层理论在稀胶体溶液，特别是DNA溶液中的应用。高电荷胶体棒之间的相互作用是根据两根棒之间以及一根棒与一个小的反离子之间的第二维里系数来展开的。相关的簇积分是用基于泊松-玻尔兹曼方程的相互作用势来评估的。该处理方法扩展到了负责卷曲DNA统计膨胀的链内排斥（排除体积效应）。该理论与三组实验数据进行了比较：DNA-盐溶液唐南膜平衡中的盐分布、不同离子强度下短DNA片段的沉降平衡以及T7 DNA在NaCl溶液中的特性粘度。在所有情况下，该理论与实验结果都吻合得很好。对于低离子强度下的沉降平衡，这种吻合并不令人信服，因为在这里，对于DNA-盐排斥的截断稀溶液展开来说，实验中的DNA浓度过高。
