IDENTIFICATION OF MONOCLONAL PROTEINS IN SERUM - A QUANTITATIVE COMPARISON OF ACETATE, AGAROSE-GEL, AND CAPILLARY ELECTROPHORESIS

A selected group of 308 sera were analyzed by capillary electrophoresi s (CE), agarose gel electrophoresis (AGE), and cellulose acetate elect rophoresis (CAE) and evaluated for abnormalities that would suggest th e presence of a monoclonal protein. The sensitivity (an electrophoreti c abnormality in sera that contained a monoclonal protein) and specifi city (a normal electrophoretic pattern in sera that did not contain a monoclonal protein) was determined for each electrophoretic procedure. CAE was the most specific procedure and CE was the most sensitive. Th e increase in sensitivity of CE was primarily due to increased detecti on of cryoglobulins and free light chains. The quantitation of the gam ma region and/or monoclonal antibody peaks by CE was similar to result s obtained by AGE. Quantitation of very large monoclonal protein peaks (> 3.0 g/dL) by on-line absorption detection (CE) yielded higher resu lts than quantitation by dye-binding (AGE).