Comprehensive Interpretation of Gel Electrophoresis Data

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• 作者：Chongli Yuan ; Elizabeth Rhoades ; Daniel M. Heuer ; Sourav Saha ; Xiong Wen Lou ; Lynden A. Archer
• 刊名：Analytical Chemistry
• 出版年：2006
• 出版时间：September 1, 2006
• 年：2006
• 卷：78
• 期：17
• 页码：6179 - 6186
• 全文大小：319K
• 年卷期：v.78,no.17(September 1, 2006)
• ISSN：1520-6882

文摘

From temperature analysis of polyacrylamide gel electrophoresis data for rigid-rod DNA analytes, it is proposedthat an entropic force term is responsible for the discrepancy between Ogston-Morris-Rodbard-Chrambach model predictions and experimental results. This entropicforce originates from reduction of the orientational freedom of anisotropic analytes in small pores of polyacrylamide gels. Time-dependent fluorescence anisotropy decaymeasurements confirm that, even in the absence of an external field, orientation of anisotropic analytes is restrictedin polyacrylamide gels. A new comprehensive model isproposed that takes this effect into consideration. Predictions based on this model are found to compare favorablywith experimental data for linear and three-arm asymmetrically branched rigid-rod DNA analytes covering abroad range of molecular aspect ratios and sizes. A newlength scale is also proposed for describing the effect ofanalyte topology on electrophoretic mobility. This lengthscale reduces to the analyte radius of gyration in the limiting cases of spherically symmetric and linear rigid-rodspecies. Based on these results, a general approach isproposed for interpreting gel electrophoresis data ofcharged analytes possessing simple and complex topologies.