Checkerboard immunoblotting (CBIB): an efficient, rapid, and sensitive method of assaying multiple antigen/antibody cross-reactivities.

A simple technique, checkerboard immunoblotting (CBIB), is described, which facilitates the examination of multiple antigen/antibody interactions, conveniently and reproducibly, using minimal amounts of reactants. Antigens, immobilized on a solid-phase membrane in parallel lanes, are allowed to react with primary antibodies, applied in lanes perpendicular to the antigens, and the reactions are developed with appropriately labeled secondary antibody and substrate. Positive reactions, at the intersections of antigen/antibody lanes, are small squares, giving a checkerboard appearance to the blot. The results are easily read visually and presented in the form of a permanent record. CBIB has wide range of applications, including the screening of hybridomas for monoclonal antibody production. With the cholera toxin (CT)-related antigens used, homologous reactions were markedly stronger then heterologous reactions.