The mechanism of formation and the receptor-binding and functional properties of the B-lymphocyte subpopulations in the various immune pathologies are the factors that can affect the basic principles of initiation of a specific immune response and its relationship with the innate immunity of an organism. Identification of the positions of the immunoglobulin receptors on the lymphocytes is the specific clinical information on more accurate disease pathogenesis and differential diagnosis. The survey has proven that the IgM C2 and C9 monoclonal antibodies interact with the bovine blood B-lymphocytes. The relative numbers of B cells in the animal peripheral blood and the variation in the positions of the Ig receptors have been determined with the method for direct immunoperoxidase staining.