Silver staining of denaturing gradient gel electrophoresis gels.

and -IgM k and l light chains did not show the presence of monoclonal components. Reduction with mercaptoethanol (1:2 dilution), which dissociates complexes but does not dissociate albumin dimers, excluded the possible formation of complexes with a1-antitrypsin. Interferences by radio-opaque agents or medications, which could lead to the appearance in the CZE electropherograms of abnormal peaks, were discarded as explanations because they are visible in the a2-globulin fraction or b region and do not show a bicuspid electrophoretic pattern (4 ). The demonstration of a double albumin line on protein electrophoresis depends on the method used for separating blood proteins. Agarose gel electrophoresis has good separation of the b and g globulins, but CZE shows improved separation of the albumin, a1, and a2 fractions (5 ). Meiers et al. (6 ) reported that the method of choice is cellulose-acetate foil electrophoresis because of its high sensitivity, but this method lacks specificity. Our results indicate that with the new capillary electrophoresis, more cases of this rare and interesting electrophoretic abnormality may be detected. However, further research is needed to confirm the clinical importance of the additional cases of bisalbuminemia detected by CZE.