ELECTRON MICROSCOPY: GASTROINTESTINAL: GI: COLON: Cytoplasm of epithelial cells, mitochondria, Golgi apparatuses. (EM-labeled); RCH/AMCJ2820, portions of at least 6 epithelial cells are seen (nuclei, basal surfaces, and apical surfaces of the cells are not seen), large intestine (cecum), mouse, absorptive epithelium. *-plasma membranes, 1-mitochondria, 2-Golgi appa