METHODS FOR ENHANCED PROTEIN PRODUCTION
The present invention provides a method of increasing protein production in a cell culture by growing cells that produce the protein (e.g., the growth phase) in a perfusion cell culture to a high cell density (i.e., at least above about 40×10 6 cells/mL) and then switching to a protein production phase, wherein the cells are cultured in a fed-batch cell culture. The present invention further provides a method for clarifying a protein from a cell culture by adjusting the pH of the cell culture to below neutral pH (i.e., below a pH of 7) and settling the cell culture, such that the cell culture separates to form a supernatant layer and a cell-bed layer, wherein the protein is in the supernatant layer.
1 . A method for clarifying a protein from a cell culture, comprising:
(A) adjusting the pH of the cell culture to below neutral pH; and
(B) settling the cell culture, such that the cell culture separates to form a supernatant layer and a cell-bed layer, wherein the protein is in the supernatant layer.
2 . The method of claim 1 , wherein the cell culture is settled for at least 30 minutes.
3 . The method of claim 1 , wherein the cell culture is settled for between 30 and 120 minutes.
4 . The method of claim 1 , wherein the pH is between 4 and 7.
5 . The method of claim 4 , wherein the pH of the buffer is preferably at the same pH as that the cell settling was done.
6 . The method of claim 1 , wherein the cell culture is an animal cell culture.
7 . The method of claim 6 , wherein the cell culture is a Chinese Hamster Ovary (CHO) cell culture.
8 . The method of claim 1 , wherein the protein is an antibody.
9 . The method of claim 8 , wherein the antibody is a monoclonal antibody.
10 . The method of claim 9 , wherein the monoclonal antibody is selected from the group consisting of a human, humanized and chimeric antibody.
11 . The method of claim 1 , wherein the protein is selected from the group consisting of enzymes, receptors, fusion proteins, cytokines, regulatory factors, hormones, antigen-binding agents, therapeutic proteins, and diagnostic proteins.