CPC C12N 5/0037 (2013.01) [C12P 21/02 (2013.01); C12N 2500/12 (2013.01)] | 11 Claims |
1. A method of culturing mammalian cells expressing a heterologous protein in a perfusion cell culture comprising:
(a) inoculating mammalian cells expressing a heterologous protein in a serum-free culture medium;
(b) culturing the mammalian cells during growth phase by perfusion with a serum-free perfusion medium; and
(c) culturing the mammalian cells during production phase by perfusion with a serum-free perfusion medium comprising potassium ions at a concentration of 30 mM to 250 mM and a molar ratio of sodium to potassium ions of less than 1,
wherein the osmolarity of the serum-free perfusion media is between 300 and 500 mOsmol/kg,
wherein step (b) is optional,
and wherein step (c) further comprises maintaining a cell density by cell bleeding, wherein cell bleeding is reduced compared to a perfusion cell culture using the same serum-free perfusion medium comprising potassium ions at a concentration of less than 30 mM and a molar ratio of sodium to potassium of more than 2 and cultured under the same conditions.
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