Attachment of rat hepatocytes in vitro to substrata of serum protein, collagen, or concanavalin A.

Isolated rat hepatocytes attach to, and spread on, the surface of polystyrene tissue culture dishes in the presence of serum. The attachment is essentially complete in 30 min at 37 °C, whereas no attachment occurs at 0 °C. Dead (trypan blue-stainable) cells do not attach; hence the plating efficiency (percentage of cells attaching) is close to the percentage of intact cells in the hepatocyte suspension. Attachment in the presence of serum is relatively independent of pH, but requires divalent cations. Mg²⁺ stimulates attachment more effectively than Ca²⁺, and a combination of both cations gives maximal attachment. Cells do not attach readily to untreated dishes in the absence of serum, but attach to and spread on dishes precoated with adsorbed serum protein, concanavalin A (ConA), or a film of collagen. The attachment-promoting activity in serum is destroyed by acid treatment, by heating to 70 °C, and by protease treatment. It is therefore most probably a protein, which, like collagen and ConA, can bind to receptors on the hepatocyte surface.