An electrophoretic difference between surface and secreted IgM of murine splenocytes

micro-chains on the surface of murine splenocytes are more heterogeneous on SDS-polyacrylamide gel electrophoresis than both secreted and intracellular micro-chains labeled with [(3)H]tyrosine. No difference in heterogeneity among cell surface, secreted, or intracellular L chains was detected. The possible role of carbohydrate in micro-chain heterogeneity is discussed.