Continuous Free-Film Electrophoresis: The Crescent Phenomenon

Abstract
Electroosmotic and laminar flow effects in continuous free-film electrophoresis cause the separated bands to assume crescent-shaped cross-sections. These are made visible by a special illumination technique. The crescent characteristics – their direction and amplitude of curvature, symmetry, and extension in depth – provide a “signature” of separation performance. This permits the operator to adjust the cell wall zeta potential for optimum resolution, to increase the useful level of sample flow rate, and to recognize and correct causes of instability.