Prospective study of serum protein capillary zone electrophoresis and immunotyping of monoclonal proteins by immunosubtraction.

Capillary zone electrophoresis and immune adsorption were evaluated for identification of serum protein abnormalities and immunotyping of monoclonal proteins. A 7-capillary, electrophoresis instrument and solid phase immunosubtraction reagents were used in a prospective study of 1,518 patients. Serum protein electrophoresis was performed by agarose gel electrophoresis and capillary electrophoresis and interpreted with regard to identification of abnormalities consistent with monoclonal gammopathies. The agarose gel electrophoresis had a sensitivity and specificity of 91% and 99%, respectively, whereas capillary electrophoresis gave results of 95% and 99%. Immunotyping of the monoclonal proteins was performed by immunofixation and immunosubtraction. Capillary electrophoresis was more sensitive than agarose gel electrophoresis for the identification of monoclonal proteins in serum. In addition, the immunosubtraction method seems technically simpler and more automated than immunofixation and represents a useful additional approach for immunotyping monoclonal proteins.