Entamoeba coli

• Mature, infective cyst in stool specimen, wet mount, Iodine-stained
• Large, spherical or ovoidal shaped cyst, 15-25 micrometer in diameter
• Usually contains 8 nuclei, but 16 nucleated cyst can be found sometimes
• Each nuclei has refractile, eccentric karyosome
• Cytoplasm is usually free of browish glycogen mass, give a clean, yellowish look