Tietz D, Chrambach A
Section on Macromolecular Analysis, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD.
Electrophoresis. 1993 Mar;14(3):185-90. doi: 10.1002/elps.1150140131.
The computer program ELPHOFIT for evaluation of the nonlinear plots of log-(mobility) vs. polymer concentration (Ferguson plots) in terms of molecular and polymer properties has been extended to yield a measure of the molecular sieving capacity of the polymer medium. The usefulness of the extended program, version 2.2, was exemplified by the evaluation of DNA shape and separation efficiency in solutions and gels of agarose and polyacrylamide, using previous reports in the literature as a data base. That application of the extended program yields the following results:(i) The size of migrating DNA can be compared with an equivalent sphere having the same free mobility for a particular set of experimental conditions. The decrease in size of the equivalent sphere with polymer concentration previously demonstrated for agarose solutions applies to all of these polymer media; it reveals a steep, hyperbolic decline of that radius in uncrosslinked polyacrylamide solutions in contrast to the shallow decline in the other three media. (ii) The separation efficiency of polyacrylamide gels exceeds that of uncrosslinked polyacrylamide solutions; the separation efficiency of agarose solutions for DNA smaller than 1 kb in length is higher than that of polyacrylamide solutions. Program ELPHOFIT 2.2 is available on request from the first author.
用于根据分子和聚合物特性评估对数（迁移率）与聚合物浓度的非线性图（弗格森图）的计算机程序ELPHOFIT已得到扩展，以得出聚合物介质分子筛能力的度量。扩展程序版本2.2的实用性通过以文献中先前的报告为数据库，评估琼脂糖和聚丙烯酰胺溶液及凝胶中DNA的形状和分离效率得到了例证。该扩展程序的应用产生了以下结果：（i）对于特定的一组实验条件，可以将迁移DNA的大小与具有相同自由迁移率的等效球体进行比较。先前在琼脂糖溶液中证明的等效球体大小随聚合物浓度的降低适用于所有这些聚合物介质；与其他三种介质中的平缓下降形成对比的是，它揭示了未交联聚丙烯酰胺溶液中该半径的急剧双曲线下降。（ii）聚丙烯酰胺凝胶的分离效率超过未交联聚丙烯酰胺溶液；长度小于1 kb的DNA的琼脂糖溶液的分离效率高于聚丙烯酰胺溶液。可应第一作者的要求提供程序ELPHOFIT 2.2。
