Trophozoite stage from culture of Entamoeba histolytica. The living trophozoites vary in size from about 10 to 60 um in diameter, depending on their degree of activity and various other conditions. The nucleus is spherical, with a diameter about one-fifth or one-sixth that of the entire ameba. It contains a small, distinct central karyosome surrounded by an unstained "halo". Iron-Hematoxylin stain x400
Hae-Seon Nam