A monoclonal antibody to Babesia divergens which inhibits merozoite invasion.

A monoclonal antibody-producing hybridoma cell line has been raised against merozoites of Babesia divergens. This antibody is strongly reactive against merozoites in an enzyme-linked immunosorbent assay (ELISA) and is also positive in an indirect fluorescent antibody test (IFAT) on preparations of live merozoites. The antibody recognizes an antigen, of molecular weight (Mr) 50-60 K by Western blot analysis on SDS-polyacrylamide gel electrophoresis (SDS-PAGE) gels. Merozoite neutralization assays show that the antibody significantly inhibits merozoite invasion of bovine erythrocytes.