Studies on the chemicals required to induce alterations of morphology and growth potential in human cell culture.

of any one of the thirteen ingredients or the addition of calcium and/or magnesium ions prevented the alteration phenomenon. The optimum concentrations of the essential chemicals were determined. A direct relationship was found to exist between the concentration of trypsin which induced cell alteration and the concentrations of calcium and magnesium ions which inhibited the conversion process. The results are discussed with reference to the possible origins of the alterable fibro blastic-like cells, as well as the possible mechanisms responsible for the alteration phenomenon.