Modified amino acids are inhouse manufactured amino acid derivatives with specific properties enabling the intensification of cell culture processes. Together, Phospho-L-Tyrosine disodium salt and S-Sulfocysteine sodium salt can be used as replacement for tyrosine and cysteine to generate highly concentrated, neutral pH feeds. Both modified amino acids eliminate the need for alkaline feeds, which are normally applied to ensure solubility and stability of the unmodified amino acids tyrosine and cysteine. Utilization of just one single, neutral pH feed is a revolutionary idea to simplify fed-batch processes.
The use of modified amino acids can furthermore have positive impacts on cell culture duration or productivity. The high feed concentration achievable using modified amino acids allows to lower the feed volume addition in biopharmaceutical manufacturing and thus may bring an increase in titer.