Quantitative studies on the behavior of the proteins of the medium during the growth of replicate cultures of the L strain

Abstract

1. 1. Replicate stationary flask cultures of the L strain cells were grown for 6 days without renewal, in a medium containing 38 per cent rat serum as the sole source of protein. 2. 2. During the growth of these cultures no change of the total protein concentration of the medium detectable by the biuret reaction occurred. 3. 3. A significant decrease of the relative concentration of the α 2 globulin fraction was the only change detected by paper electrophoresis. 4. 4. The decrease of the α 2 globulin fraction was not related to the process of the attachment of the cells to the glass surface of flasks. 5. 5. The decrease of the α 2 globulin fraction was a linear function of time and its rate was related to the growth rate of the cells.