Hybridomas were produced from spleen cells of BALB/c mice immunized with a membrane preparation from Neisseria meningitidis group A strain 4402 and S194/5.XXOBU.14 myeloma cells. The hybridomas were screened for secretion of
antibodies suitable for an
enzyme-linked
immunosorbent assay (ELISA) diagnostic for group A
meningococcal meningitis. One hybridoma antibody, 3G7, was directed against the pilus
protein. This antibody bound to all six
lipopolysaccharide and
protein group A meningococcal serotyping strains, as well as to meningococcal strains from serogroups C, W135, and Y, but not to a strain of Escherichia coli, Haemophilus influenzae type b, or to two or more strains of Streptococcus pneumoniae, Neisseria gonorrhoeae, and Salmonella typhi. The ELISA used on antibody,
antigen, antibody-conjugate sandwich. Rabbit anti-meningococcal serum was the coating antibody for the antibody sandwich, cerebrospinal fluids contained the
bacterial antigens, and 3G7-alkaline
phosphatase conjugate was the detecting antibody. The
monoclonal antibody conjugate ELISA system was able to detect group A meningococcal
antigens in 21 of 25 cerebrospinal fluid specimens that were positive in an immune rabbit serum conjugate ELISA; cerebrospinal fluid samples from patients with
Haemophilus meningitis served as the controls. Counterimmunoelectrophoresis detected meningococcal
antigens in 16 of the same 25 cerebrospinal fluid samples.