This video describes the role of the fermentation process in the creation of biological products and illustrates commercial-scale fermentation at a cellular level. Included are descriptions of types of fermentation (intracellular, extracellular), types of cells (aerobic, anaerobic), and cell nutrition (media components). The program follows the production of a batch of Green Fluorescent Protein (GFP) from preparation through harvesting, including growth of seed stock, scaling up, and life cycle growth pattern phases (lag, exponential/log, stationary, death). Featured throughout is the monitoring of various production process parameters, including time, temperature, pressure, pH, agitation, etc.