MULTIPLICATION OF ANIMAL CELLS IN SUSPENSION MEASURED BY COLONY COUNTS

Abstract

When animal cells of 2 different strains were withdrawn from populations growing in suspension, they multiplied, without an appreciable lag, to form colonies. While the percentage of cells that formed colonies varied widely when they were plated from the stationary phase of growth, 75% of the cells gave rise to colonies when plated at any time during the logarithmic period. Almost 100% of the cells in the logarithmic phase grew into colonies if they were plated over feeder layers of X-irradiated cells, showing that all, or nearly all, of the cells were capable of multiplying if provided with the proper nutritional environment. The cell-culture systems described should facilitate a variety of studies on the physiology and biochemistry of animal cells.