Method of determining virus removal from a sample containing a target protein using activated carbon

1. A method for determining whether activated carbon can be used for the removal of viruses from a sample containing a target protein having a protein concentration equal to or greater than 0.2 g/L, the method comprising the steps of: (a) providing a portion of a sample comprising a target protein having a protein concentration equal to or greater than 0.2 g/L: (b) adding a virus to the portion of the sample in the amount ranging from 10 4 to 10 9 PFU/mL; (c) flowing the portion of the sample through a column packed with activated carbon; (d) collecting one or more flow-through fractions from the column; and (e) measuring the virus amount in the one or more flow-through fractions, wherein a reduction in the virus amount in the one or more flow-through fractions by at least 3.0 LRV is indicative that activated carbon can be used for the removal of viruses from the sample.

2. The method of claim 1 , wherein the sample comprises a protein concentration equal to or greater than 0.5 g/L.

3. The method of claim 1 , wherein the sample comprises a protein concentration equal to or greater than 1 g/L.

4. The method of claim 1 , wherein the sample comprises a pH in the range of 3.0-10.0 and/or a salt concentration less than 0.5M.

5. The method of claim 1 , wherein the virus is a parvovirus.

6. The method of claim 5 , wherein the parvovirus is minute virus of mice virus.

7. The method of claim 1 , wherein the sample comprises a cell culture feed.

8. The method of claim 7 , wherein the cell culture feed is a CHO cell culture feed.

9. The method of claim 1 , wherein the target protein is a recombinant protein.

10. The method of claim 1 , wherein the target protein is a therapeutic protein.

11. The method of claim 1 , wherein the target protein is an antibody.

12. The method of claim 11 , wherein the antibody is a monoclonal antibody.

13. The method of claim 1 , wherein the sample comprises a clarified cell culture feed.

14. The method of claim 13 , wherein clarified cell culture feed is obtained using one or more methods selected from centrifugation, settling, depth filtration, screen filtration, flocculation, use of a stimulus responsive polymers and pH change.

15. The method of claim 1 , wherein the sample comprises an eluate obtained from a Protein A chromatography column, wherein the eluate comprises the target protein.

16. The method of claim 1 , wherein step (e) employs one or more methods selected from the group consisting of 50% tissue culture infectious dose (TCID50) assay, plaque-forming unit assay, focus-forming unit assay, lethal dose 50% assay, hemagglutination assay, fluorescent focus assay (FFA), bicinchoninic acid assay (BCA), single radial immunodiffusion assay (SRID), quantitative polymerase chain reaction (qPCR), enzyme-linked immunosorbent assay (ELISA), and transmission electron microscopy.