Study of the population dynamics of human diploid cell strain WI-38: IV. Volume of the medium and of the air phases

Abstract

The yield of WI-38 cells in stoppered bottle cultures is directly dependent on the volume of the medium. This is a logarithmic function in a range of 0·2–1·0 ml/cm 2. Smaller (0·1 ml/cm 2) or larger (1·9 ml/cm 2) volumes of the medium give lower cell yields than expected. A twofold increase in the volume of the medium produces a 0·2 log 10 increase in the cell yield. The positive effect on the cell yield achieved by increasing the volume of the medium is greater than the effect achieved by introducing a corresponding increase in the total quantity of the calf serum at a constant volume of the medium. Increasing the concentration of the serum twofold raises the cell yield by about 0·05 log 10. With the quantity of the serum in the medium kept constant the cell yields can be varied by varying the volumes of the medium. The increased cell yield effected by increasing the volume of the medium diminishes with increasing ‘age’ of the cell population.