A new active cooling system is available for the ambr micro bioreactor. The system uses circulated chilled fluid to adjust and maintain the cell culture temperature to between 20°C and 40°C. This temperature range makes it possible to predict cells’ performance in large-scale bioreactors and optimize conditions for both increased protein production and modulation of product quality in mammalian cultures. The lower temperatures also add the potential to support optimization of cell growth and protein expression with insect cell lines such as SF9, SF21, and Hi5.