Use and abuse of sepharose-conjugated antibodies for the isolation of lymphocyte-surface immunoglobulins.

Immunoadsorbents of Sepharose-4B-conjugated antibodies were shown to be suitable for the characterization, by subsequent SDS-polyacrylamide gel electrophoresis, of splenocyte-membrane Immunoglobulin (Ig) solubilized by detergent lysis of surface 125I-labelled cells. However, high non-specific binding of 125I-labelled lymphocyte-membrane components to Sepharose-4B prevented accurate quantition of Ig in such lysates. 125I-labelled lymphocyte-membrane components solubilized by metabolic release also showed high non-specific binding to Sepharose-4B, and this interfered with both quantitative and qualitative analysis of Ig solubilized in this manner. Initial attempts to overcome the nonspecific binding of 125I-labelled lymphocyte-membrane components to Sepharose-4B were unsuccessful, and attention is drawn to the technical problems of using Sepharose-4B as a matrix for solid-phase immunoadsorbent studies of lymphocyte-membrane Ig.