The binding of anti‐immunoglobulin antibodies to rat thymocytes and thoracic duct lymphocytes

Abstract Anti‐rat immunoglobulin antibodies were purified by acid elution from immunoadsorbents, and their binding to rat thoracic duct lymphocytes and thymocytes studied. Satisfactory binding was only achieved when pepsindegraded reagents were used and anomalous results were obtained if aggregated antibody was present. From the thoracic duct lymphocytes of the PVG/c strain rat, 40–50 % of cells bound 20000–150000 molecules of anti‐rat Fab antibody, or 8000–60000 molecules of anti‐IgM reagent. Only 2.5 % of the cells bound more than 8000 molecules of anti‐IgG 2a+2b antibody and few thymus cells bound any antibody at this level. Thoracic duct lymphocytes without large amounts of surface immunoglobulin also bound anti‐Fab specifically. The binding was in the range of 200–3000 molecules per cell.