With the number of peptones that are available, it can be time and resource prohibitive to perform all of the testing required to select the ideal peptone.  As a result, the actual production potential of the cell line is not achieved.  An understanding of how to select the peptones for evaluation, how to screen them to find the best candidate, and how to apply the selected peptone or peptones to the particular process are all critical aspects of peptone supplementation.  These methods were successfully applied to multiple production cell lines.  In each case, the optimal peptone optimization scheme was quickly identified, resulting in significant improvements in protein production.