MICROCALORIMETRIC MEASUREMENT OF AEROBIC CELL-METABOLISM IN UNSTIRRED CELL-CULTURES

Studies of cell metabolism in small-volume, unstirred calorimeters has been limited by the problem of oxygen diffusion to the cells. Many cell types settle to the bottom of the sample container and become essentially anaerobic. Cells subjected to these conditions generally die, or when capable, alter metabolism to anaerobic pathways. Metabolic heat measurements in such conditions do not reflect normal metabolism and provide little information about normal metabolic rates. To avert this problem, the densities of the media supporting growth of animal and plant cells were increased by addition of sterile solutions of Percoll, causing cells to float at the surface of the media where they could readily absorb oxygen. Under these conditions, a wide range of cell types were studied. Plant, microbial, and animal cells could be analyzed for responses to metabolic effectors or environmental factors which influence growth. © 1990.