Online monitoring of oxygen in spinner flasks.

We show the application of a novel optical on-line sensor fixed in spinner flasks for the online monitoring of dissolved O(2) concentrations during mammalian cell growth. Using this sensor that requires only minute changes to the flask to be made, we could determine the volumetric O(2) transfer coefficient as well as O(2) consumption rates. Under normal growth conditions the cells did not undergo O(2) limitation. Also, the transfer of O(2) from the atmosphere to the spinner flasks is influenced by the use of screw caps. The on-line measurement was further applied to determine the O(2) uptake rates which can then be used to monitor the metabolic state of the cells and also for online process monitoring.