Preparation of anti-beta-1C antisera and their use in fluorescent antibody techniques.

Antisera against components of guinea-pig complement were raised in rabbits by: (1) Using as antigen a suspension of killed Proteus species bacteria which had been allowed to combine with their homologous antiserum in the presence of guinea-pig complement in optimum proportions. (2) By injection of the β1C component of guinea-pig complement adsorbed to zymosan particles. The antisera raised by the two methods contained antibodies mainly against the β1C component of complement. When coupled with FITC both antisera were found useful in detecting sites of complement fixation. The fluorescence anti-complement technique was found four times more sensitive than the indirect method for detecting antigen—antibody reactions in the presence of diminishing concentrations of antigen. It was only twice as sensitive for detecting antigen—antibody reactions in the presence of diminishing concentrations of antibody. The comparisons were based upon both visual assessment and photometric measurement. Coupled antisera raised by the first method gave brighter specific fluorescence than antisera raised by the second method when used in the highest concentration which did not give non-specific staining. The usefulness for detection of viral antigens of sera raised by both methods is discussed.