By Dr. Martin Schilling, Senior Product Manager for Cell Culture Ingredients, Evonik Health Care
While fed-batch processes remain state-of-the-art in the cell culture-based production of biopharmaceuticals, perfusion-based processes are increasingly being adopted to further increase productivity. Both process systems require concentrated media to replenish nutrients and avoid productivity loss caused by dilution. However, the solubility of amino acids can quickly become a limiting factor in the preparation of concentrated media. With a solubility of less than 0.5 g / liter in water at neutral pH, L-Tyrosine is especially challenging.
One approach that is being rapidly adopted by the industry is to overcome these challenges by replacing such amino acids with dipeptides. In order to increase solubility for free L-Tyrosine at a neutral pH, Evonik chemically couples L-Tyrosine to glycine via a peptide bond to create the dipeptide known as cQrex® GY (glycyl-L-tyrosine).