C3 and non-Hodgkin lymphoma: Five samples of tonsil, 10 reactive lymph nodes and 65 consecutive cases of non-Hodgkin lymphoma (NHL) were evaluated in suspension phenotyping with the monoclonal antibodies alpha Leu-I, alpha Leu-2a, alpha Leu-3a, OKT1, OKT3, OKT4, OKT6, OKT8, W6/32, 26/114, DA-2, 2DI, J5, AN51 and OKT9 together with conventional surface marking by rosetting (E, Fc gamma, Fc mu, C3b, C3d) and staining for surface and cytoplasmic immunoglobulin (SIg, CyIg) heavy and light chain classes.