Size Fluctuations Can Explain Anomalous Mobility in Field-Inversion Electrophoresis of DNA

Abstract

We extend the reptation model of DNA gel electrophoresis by replacing the tube by a chain of narrow "straits" connecting open "lakes." The DNA chain can accumulate easily in the lakes, thus allowing large fluctuations in the length of the chain. Unlike the standard model, this model, simulated on a computer, shows a sharp minimum in mobility as the period is varied with periodically reversing fields, similar to experiments.