Control off Some Cell-Contact Reactions in Tissue Culture2

Abstract

The degree of contact inhibition, a contact property shown by normal but not by tumor cells, produced in chick-heart fibroblasts from 9-day-old embryos grown in a liquid medium of serum, embryo extract, and saline, decreases with increasing embryo-extract concentration and with increasing age of the culture. Contact inhibition is controlled in part by the nature of the culture medium, but its display is not directly dependent on the speed of movement of the cell, though it is suggested that both may have a common controlling mechanism. It is not related directly to the incidence of mitosis past or present, but depends partly on the density of cell population.