Abstract
Monoclonal antibodies ( mAbs ) against black rockfish Sebastes schlegeli serum immunoglobulin M ( IgM ) were developed, which showed a specific reaction with the heavy chain of S. schlegeli IgM in Western blotting and with surface IgM positive ( sIgM + ) lymphocytes in indirect immunofluorescence. mAb 2A6 was employed to investigate the antibody and sIgM + lymphocyte responses of S. schlegeli injected with inactivated Edwardsiella tarda , by ELISA and flow cytometry. Compared with controls, the level of specific antibodies and the percentage of sIgM + lymphocytes both increased in the immunized fish and simultaneously reached their peaks at day 35 after immunization.