Rapid serotyping of groups A, B, and C meningococci by rocket-line immunoelectrophoresis and co-agglutination.

Rocket-line immunoelectrophoresis (R-LIE) with antigen containing intermediate gel, and co-agglutination utilising protein A-containing staphylococci coated with specific antibodies, were adapted for serotyping the prototypes of group B meningococci. Both were found to have 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 tests 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 with carriers were serotyped and the results with all three methods were in agreement.