FIG. 2.

Reactivity of MAb 4E9 with C. parvum stages as determined by IF. (A and B) Oocysts. Material shed from excysting oocysts (A) and the surface of newly excysted sporozoites (arrow) (B) is labeled. (C) Sporozoites. The surface and apical region of sporozoites and of material shed in trails (arrow) from sporozoites allowed to glide on poly-l-lysine coated slides are labeled. (D) Intracellular stages. Meronts and merozoites newly emerged from them (arrow) in infected Caco-2A cells are labeled.