CHO|ONE Feed 1 and Feed 2 are feed additives (supplements) especially matched to the core medium CHO|ONE E. Combining these products increases fed-batch productivity 3- to 5-fold compared to batch culture conditions. CHO|ONE Feed 1 contains concentrated amino acids, vitamins, salts, trace elements, and a carbon source. Further, CHO|ONE Feed 1 comes without Insulin & without L-Glutamine and is supplemented with Pluronic™. CHO|ONE Feed 2 is a balanced formulation of selected amino acids in a concentrated form. Please refer to the proposed protocols to facilitate easy and efficient identification of a feeding strategy. The innovative CHO|ONE Media System™ was invented for small- and large-scale protein production and can be used as growth medium for CHO-K1, CHO-S, and CHO-DG44 cell lines. The CHO|ONE Media System™ was specially designed in close cooperation with our biopharmaceutical cooperation partner and is highly suitable for fed-batch cultures. It improves the yield and concentration of recombinant proteins through the optimization of a selection of essential nutrients and growth-promoting factors.