Spatially periodic instability occurring in moving boundary electrophoresis experiments

Abstract

While carrying out moving boundary electrophoresis experiments in gels, an unusual periodic disturbance of the interface was noted. This disturbance occurs when the mobility of the trailing ion exceeds that of the leading ion. A simplified model neglecting diffusion has been developed to demonstrate the physical basis for the boundary instability. By the use of dimensional analysis it can be shown that the wavelength of the instability is independent of electrolyte concentration and is inversely related to applied voltage. These predictions are in accord with experiment.