(337a) Electrophoresis Of DNA Molecules Confined In Virtual Nanochannels

We present the first theoretical and computational study of polyelectrolytes undergoing electrophoresis in free solution while being squeezed by a lateral mechanical force (a harmonic potential with a cylindrical geometry) transverse to the direction of the electric field. We show that the polylectrolyte retains its ?free-draining? properties in such situations, a result which brings a new perspective on a most fundamental property of charged biopolymers. The electrophoretic mobility of the chains can be described in terms of a local model where the relevant effective segment is oriented along the direction of motion. This description predicts an increase in mobility as the squeezing potential is strengthened, in agreement with our Molecular Dynamics simulation data. Interestingly, our data also suggest a possible novel separation scheme. This is quite different from the previously examined case where a mechanical force is applied at the extremity of a polyelectrolyte in the direction of the its net motion (as in End-Labelled Free-Solution Electrophoresis, or ELFSE) since such longitudinal forces are known to affect the free-draining behaviour.