Process controls are used to maintain an optimal physical and chemical environment within a bioreactor (cell culture vessel used to incubate cells at a high density). This interactive scrollable explains what process controls are and why they are necessary to maintain optimal conditions for culturing cells in a bioreactor, reviews the different types of probes that are used to monitor the cell culture in a bioreactor, and describes how computer programs are used to monitor process variables and make automated adjustments to cell culture conditions in a bioreactor.