Monoclonal antibodies against Bonamia ostreae (Protozoa: Ascetospora), an intrahaemocytic parasite of flat oyster Ostrea edulis (Mollusca: Bivalvia)

The protozoan Bonamia ostreae (Ascetospora), a parasite of the flat oyster Ostrea edulis was purified by differential and isopycnic centrifugations. Mice of the strain Balb/c were immunized with purified parasites and hybridomas were prepared by fusion of immunized mouse splenocytes with the mouse myeloma cell line P3-X63-Ag8-653. From the fusion, 12 clones were isolated and saved. The resulting antibodies were characterized with a solid phase radioimmunoassay (RIA). Antibodies from 7 clones reacted only with B. ostreae and not with normal host tissue. Although some of the antibodies appeared to react with the same epitopes, at least 4 clearly different epitope specificities were identified.