Mass spectrometry: a tool for on-line monitoring of animal cell cultures.

The magnetic sector mass spectrometer is able to detect oxygen uptake and carbon dioxide production rates from animal cell cultivations performed in 101 bioreactors. Such data have not been available with the use of classic exhaust gas analysis applying paramagnetic analyzers and infra-red sensors due to the insensitivity of the apparatus available. In the course of the present work we were able to demonstrate, that the oxygen uptake rate correlates to the number of viable cells. Additionally oxygen uptake rates supplied on-line information about the actual physiology of the cells: When the rates changed during the cultivation process, this immediately indicated the occurrence of limitations of components in the medium. The information could be useful in timing key events, such as performing splits or harvesting the bioreactor.