Channel thickness variations could degrade resolution in electrophoresis

Variations in the lateral dimensions of capillaries and ultrathin gels along their length could lead to a distortion of the sample zone because charged particles traveling near the wall must travel a longer distance under a smaller field than particles traveling along the centerline. The size of the effect is computed by solving Laplace's equation for the potential everywhere in a conducting slab with a discontinuity in the lateral discontinuity in the lateral dimensions and integrating the travel time along different streamlines.