Sample application position and the resolution of protein separation on the Beckman Microzone Electrophoretic System

Many clinical laboratories use the Beckman Microzone electrophoretic system (Beckman Instruments Inc. Fullerton, CA 92634) for serum protein separation. Although detailed instruction is supplied in the manufacturer's manual (1) for protein separation, the effect of different sample application positions on the cellulose acetate membrane is not discussed. We have processed the serum specimen in various application positions and found that there is a definite relationship between the resolution of fractionated protein bands and the application position, particularly with specimens from patients with monoclonal gammonpathies. The resolution of the protein bands increases as the sample is applied closer to the anode end of the cellulose acetate strip. Although studies were carried out on the Beckman electrophoretic system, a similar application effect may be anticipated with other electrophoretic systems.