Apparatus and a method for continuously harvesting a biological substance produced by a cultured cell

1 . An apparatus for continuously harvesting a biological substance produced by cultured cells, wherein the apparatus comprises:

(a) filter 1 which is at least one filter(s) having pore size(s) which do(es) not allow the cells to pass through the filter, but allow the biological substance to pass through the filter,

(b) filter 2 which is at least one filter(s) having pore size(s) which do(es) not allow both the cells and the biological substance to pass through the filter, but keep fluid-flow-through of the filter,

(c) a regulator that regulates the filtration rate of filter 1, and

(d) a regulator that regulates the filtration rate of filter 2

wherein filter 1 and filter 2 are fluidly connected to an apparatus for culturing the cells in a parallel manner and

wherein the (c) and (d) regulate the ratio of flow rate of cell culture through filter 1 and filter 2 to concentrate the biological substance first and then do not concentrate the biological substance in harvest liquid.

2 . The apparatus of claim 1 , wherein filter 1 and filter 2 are fluidly connected to the apparatus for culturing the cells

(a) directly and separately,

(b) via a branched pipe, or

(c) a combination of (a) and (b).

3 . The apparatus of claim 1 , wherein filter 1 has a pore size of about 0.08 μm to 0.5 μm.

4 . The apparatus of claim 1 , wherein filter 2 has a molecular weight cut-off (MWCO) of 50 kD or less.

5 . The apparatus of claim 1 , wherein either or both of filter 1 and filter 2 is/are alternating tangential flow (ATF) filter(s) or tangential flow filtration (TFF) filter(s).

6 . The apparatus of claim 5 , wherein either or both of filter 1 and the filter 2 is/are hollow fiber filter(s).

7 . The apparatus of claim 1 , wherein,

the number of filter(s) in filter 1 is 1, 2, 3 or more, and/or

the number of filter(s) in filter 2 is 1, 2, 3 or more.

8 . The apparatus of claim 1 , wherein filter 1 has a pore size of about 0.1 μm to 0.4 μm.

9 . The apparatus of claim 1 , wherein filter 1 has a pore size of about 0.2 μm.

10 . A system for producing a biological substance, wherein the system comprises:

(a) a cell culture apparatus with a basal medium and a feed medium in a perfusion manner; and

(b) the apparatus of claim 1 .

11 . The system of claim 10 further comprising a biological substance capturer.

12 . The system of claim 10 further comprising a microsparger.

13 . A method for continuously harvesting a biological substance produced by cultured cells, comprising:

continuously harvesting a biological substance produced by cells cultured in an apparatus for culturing the cells with a basal medium and a feed medium in a perfusion manner with an apparatus comprising:

(a) filter 1 which is at least one filter(s) having pore size(s) which do(es) not allow the cells to pass through the filter, but allow the biological substance to pass through the filter, and

(b) filter 2 which is at least one filter(s) having pore size(s) which do(es) not allow both the cells and the biological substance to pass through the filter, but keep fluid-flow-through of the filter; and

(c) a regulator that regulates the filtration rate of filter 1, and

(d) a regulator that regulates the filtration rate of filter 2,

wherein filter 1 and filter 2 are fluidly connected to the apparatus for culturing the cells in a parallel manner, and

wherein the (c) and (d) regulate the ratio of flow rate of cell culture through filter 1 and filter 2 to concentrate the biological substance first and then do not concentrate the biological substance in harvest liquid.

14 . The method of claim 13 , wherein the cells comprise mammalian cells.

15 . The method of claim 14 , wherein the mammalian cells comprise CHO (Chinese Hamster Ovary) cells, hybridomas, BHK (Baby Hamster Kidney) cells, or myeloma cells.

16 . The method of claim 13 , wherein the biological substance is chosen from receptors, enzymes, fusion proteins, blood proteins, multifunctional proteins, viral or bacterial proteins, and immunoglobulins.

17 . The method of claim 16 , wherein said blood proteins are from the blood coagulation cascade.

18 . The method of claim 16 , wherein said multifunctional proteins are erythropoietin.

19 . The method of claim 16 , wherein said viral or bacterial proteins are used in vaccines.

20 . The method of claim 16 , wherein said immunoglobulins are antibodies or multi-specific antibodies.

21 . The method of claim 20 , wherein said antibodies are IgG or IgM.

22 . The method of claim 20 , wherein said multi-specific antibodies are bi-specific antibodies.

23 . A method for producing a biological substance, comprising:

culturing cells in an apparatus for culturing the cells with a basal medium and a feed medium in a perfusion manner; and

continuously harvesting a biological substance produced by the cultured cells with an apparatus comprising:

(a) filter 1 which is at least one filter(s) having pore size(s) which do(es) not allow the cells to pass through the filter, but allow the biological substance to pass through the filter, and

(b) filter 2 which is at least one filter(s) having pore size(s) which do(es) not allow both the cells and the biological substance to pass through the filter, but keep fluid-flow-through of the filter; and

(c) a regulator that regulates the filtration rate of filter 1, and

(d) a regulator that regulates the filtration rate of filter 2,

wherein filter 1 and filter 2 are fluidly connected to the apparatus for culturing the cells in a parallel manner, and

wherein the (c) and (d) regulate the ratio of flow rate of cell culture through filter 1 and filter 2 to concentrate the biological substance first and then do not concentrate the biological substance in harvest liquid.