Monoclonal antibodies demonstrating GABA-like immunoreactivity.

Mouse monoclonal antibodies (mAb) to GABA were developed following immunization with GABA coupled to bovine serum albumin (GABA-BSA). The selection of hybridoma cell lines producing antibodies which reacted with GABA-BSA but not with glutamate-BSA conjugates as well as the characterization of chosen mAb was performed by enzyme linked immunosorbent assays (ELISA). The five mAb selected were all of the IgG class and displayed different patterns of cross reactivities with the amino acid- and dipeptide-BSA conjugates tested. MAb 3A12 reacted approximately 4,000 times better with GABA-BSA than with beta-alanine-BSA conjugates according to serial dilution experiments of the antibody in ELISA. Immunoreactivity was even lower for other conjugates tested including glycine-, taurine-, glutamate-, and glutamine-BSA. Immunohistochemical results in rat and chicken brain indicated that the patterns of GABA-like immunoreactivity observed with these mAb were consistent with the available information on the distribution of GABA-containing neurons.