Fig. 4.
P34 of Cryptosporidium parvum (Cp-P34) appears on the sporozoite surface and is secreted in trails. (A) Fluorescent micrographs (600x) localize bound single-domain camelid antibody (VHH)dimers to non-permeabilized C. parvum sporozoites and sporozoites permeabilized by drying. Lack of permeabilization is confirmed by propidium iodide (PI) exclusion and by the reduced binding of anti-Cp-gp900 VHH dimer (JMP-F7/JMP-F7), which only binds Cp-gp900 accessible on the sporozoite surface or in trails. Scale bar = 5μm. (B) Anti-Cp-P34 VHH dimer (JJS-A6/JJS-A11) binding trails left behind gliding sporozoites. Scale bar = 5μm.