Antibodies are produced by naive B cells and are called plasma cells. These cells express immunoglobulins on their surface. In the early stages, B cells first show intracellular μ-chains and then surface IgM. Through the process described earlier. these cells can later express IgG, IgA, or IgE, phenomenon known as isotype switching. The final type of surface immunoglobulin determines the class of antibody secreted.