Entamoeba coli

Entamoeba coli. Trophozoite in fecal smear (trichrome stain, oil immersion). The nucleus in this trophozoite is somewhat atypical in that the karyosome is smaller than usual and is centrally placed, whereas in most trophozoites of E. coli it is large and more eccentric in position. However, the peripheral chromatin of this organism is blocklike in its distribution on the nuclear membrane. The cytoplasm is vacuolated.