Similar to fibroblasts, epithelial cells typically migrate through cycles of lamellipodial extension and contraction. Unlike fibroblasts, however, epithelial cells tend to form small colonies and migrate in groups in culture, as demonstrated by the Madin-Darby ovine kidneys presented in this digital video. Note, the cells in the center of the colony do not exhibit lamellipodial activity and are, consequently, carried along by the cumulative action of the ruffling membranes along the free margins of other cells in the colony.

The colonial behavior of epithelial cells in culture is reflective of their activity in the body, where they characteristically are joined together to form contiguous sheets that line internal and external surfaces. The integrity of the sheets must be retained in order that they can successfully serve as barriers against the diffusion of various molecules. In contrast, fibroblasts enjoy a much more independent existence in vivo, being scattered throughout connective tissue unless they must migrate to a particular area of the body to aid in the healing of a wound.

The nuclei present in the MDOK cells are readily observable during the high speed playback of the time-lapse sequence, as are the nucleoli they contain. The profuse granular material concentrated around the nuclei consists of numerous mitochondria. The continuous movements of the granules indicate the dynamic nature of the power-generating organelles. Intracellular passages of mitochondria are greatly influenced by the cellular network of microtubules.