Location of cellular adhesions to solid substrata

Micromanipulation and time lapse cinemicrography were used to locate the adhesions to glass and polystyrene formed in culture by a variety of different cell types. These adhesions were observed to be confined to relatively narrow areas near the cell margins, principally in the vicinity of ruffling activity. During mitosis and after certain treatments, cell-substratum adhesion was found to be restricted to many tiny points connected to the cell body by narrow, nearly invisible retraction fibers. The relationship of these phenomena to cell locomotion, contact inhibition, and contact retraction is discussed.