FIG 3.

Permanent-stain options for various organisms, identified from left to right. (First row) Wheatley's trichrome stains of a Giardia lamblia trophozoite, an Entamoeba histolytica trophozoite with ingested RBCs, an Entamoeba coli cyst with red chromatoidal bars, and a Chilomastix mesnili cyst; (second row) iron-hematoxylin stains of a Dientamoeba fragilis trophozoite, Giardia lamblia cysts, an Entamoeba coli cyst, and an Iodamoeba bütschlii cyst; (third row) modified acid-fast stains of large Cyclospora cayetanensis organisms (both stained and unstained), a medium-sized Cryptosporidium sp. (with small artifacts), large Cyclospora cayetanensis organisms (with medium-sized Cryptosporidium sp. cells and a small artifact) (note that not all Cyclospora oocysts stain with modified acid-fast stain), and Cryptosporidium sp. organisms (note the presence of sporozoites in some oocysts [not seen in Cyclospora]); (fourth row) an iron-hematoxylin–modified acid-fast combination stain of Giardia lamblia and Cryptosporidium sp., a modified acid-fast–modified trichrome–Ryan blue combination stain of Cystoisospora belli microsporidial spores, a modified trichrome–Ryan blue stain of microsporidial spores, a modified trichrome–Weber green stain of microsporidial spores; (fifth row) DFA stain of Cryptosporidium oocysts (apple green color), autofluorescence of Cyclospora cayetanensis oocysts, Calcofluor white staining of microsporidial spores (in the circle), and a combination modified acid-fast–modified trichrome stain of Cryptosporidium oocysts (pink) and microsporidial spores (in circle).