<p>The present application describes an optimized medium for growth of mammalian cells as well as polypeptide production. The cell culture medium is characterized by a Sow ratio of sodium to potassium ions, it further relates to the method of producing polypeptides using such cell culture media. Sn another aspect, the method of polypeptide production can also comprise a temperature shift and/or a pH-shift to further optimize growth and product yield.</p>
