Abstract: During growth of tissue culture in a controlled atmsophere incubator the oxygen (another environmental gas) is dynamic controlled according to an oxygen profile (or other profile). Gaseous oxygen concentration is deliberately changed over time in a precise and reproducible way, with other parameters being held constant, or with other controlled parameters being changed simultaneously or sequentially. Oxygen profile is developed based on the amount of gas phase oxygen needed to maintain the dissolved gas in the culture medium at a desired level. A gas controller is programmed with the gas profile, and the oxygen is dynamically controlled according to the oxygen profile. The specific sequence and timing of changes in gaseous oxygen concentration that best indirectly regulate the desired dissolved oxygen concentration in the culture media inside open culture vessels that are placed inside the incubator.