Rocket-line immunoelectrophoresis (R-LIE) with antigen containing intermediate gel and co-agglutination utilizing protein A-containing staphylococci coated with specific antibodies were adapted for serotyping the prototypes of group B meningococci. Both had the same specificity as agar gel double diffusion (AGDD) but they were more sensitive and more rapid than AGDD. R-LIE required, like AGDD, the extraction of relatively large quantities of bacteria, while the co-agglutination method, performed as a slide agglutination test with results within a few minutes and no need of special equipment, required only a small amount of heated whole meningococcal cells. Meningococcal strains of serogroups B, C and A from patients and carriers were serotyped and the results with all 3 methods were in agreement.