Screening of sera for antibodies to foot-and-mouth disease viral antigens by radial immunodiffusion.

Radial immunodiffusion procedures have been developed for testing bovine sera for the presence of antibody activity against three foot-and-mouth disease virus types and a virus infection-associated antigen. Reactions with virus antigens were obtained as early as 4 days after infection, and the virus type causing the response was identified. The procedure had the advantages of great sensitivity for the detection of antibody and the ease with which antibodies to a variety of antigens could be detected.