Color enhanced transmission electron micrograph of a rat embryo liver cell showing centriole (blue). A centriole is a small, cylindrical cell organelle, seen near the nucleus in the cytoplasm of most eukaryotic cells, that divides in perpendicular fashion during mitosis, the new pair of centrioles moving ahead of the spindle to opposite poles of the cell as the cell divides: identical in internal structure to a basal body. Magnification on negative 19,200x. Magnification in print 76,800x.