The lack of effect of heparin on mitosis in strain L cells.

There has been considerable controversy about the action of heparin on mitosis. Early workers in tissue culture routinely used heparizined plasma without apparent inhibition of growth (2). Later, however, several investigators reported that hepa rin inhibited mitosis either in vitro or in vivo (1, 4, 5, 15), although others found it was not in hibitory (8, 10, 14). A search is being made in our laboratory for a mitotic inhibitor which will not interfere with other cellular functions. Heparin was accordingly tested for its effect on mitosis on strain L cells.