Characterization of recombinant scFv antibody reactive with an apical antigen of Eimeria acervulina

The chicken monoclonal antibody (mAb), 6D-12-G10, reacts with an apical com plex protein at the anterior tip of E. acervulina sporozoites that inhibits parasite invasion in vitro. Because this mAb was produced at low amount fr om the original hybridoma cells, an scFv antibody was constructed by amplif ication of the corresponding V-H and V-L genes and expressed in E. coli. Th e scFv antibody was produced at a minimum of 7 mg l(-1) and exhibited virtu ally identical antigen reactivity as the original mAb.