Cell culture feeding strategies are typically developed over a series of experiments in which various feeding volumes and times are applied based on daily offline sampling data.  We have implemented automatic online sampling with controlled feedback as a process development tool in which the cell metabolism and physiology of the culture dynamically determine the nutrient requirements of the culture.  Using this strategy , monoclonal antibody production increased by over 50% and product quality was not affected when compared to the previously defined cell culture process.  We have applied this technique to at least two different cell lines using different nutrient feed components.  When networked into the bioreactor control equipment, more complex process control can be achieved.  This approach can be used improve product yields and significantly reduce process development timelines.