Capillary electrophoresis of DNA in entangled polymer solutions.

Electrophoretic separations of DNA restriction fragments were performed in solutions of hydroxyethylcellulose (HEC) using capillary electrophoresis. Rheological studies confirmed that the entanglement threshold (phi*) for the solution is ca. 0.003 g/ml, in good agreement with theoretical predictions. A mesh size an order of magnitude smaller than that found in agarose gels was calculated using polymer-entanglement theory and was confirmed by electrophoretic measurements. Electrophoretic migration was shown to follow the Ogston regime under most conditions. An approach for obtaining smaller mesh sizes is presented.