Microscopy images of Cryptosporidium parvum and hominis sporozoites. Panel A and B. Energy-filtering transmission electron microscopy (EFTEM) of C. hominis sporozoite sections obtained from a clinical isolate. Panel c and e. EFTEM of C. parvum sporozoites showing an ultrastructure mitochondrion image (c) and sporozoites within an oocyst (e). Panel e. OOcysts and free sporozoites of C. parvum during an excystation processed followed in optical microscopy by DAPI (blue) and SYTOX (green) DNA staining. Arrows show the nuclear membrane-associated mitochondrion structure; nu, mi and dg symbols indicate nucleus, micronemes and dense granules, respectively