Methods of replicating a large scale eculizumab production cell culture

A method of replicating a large-scale eculizumab production cell culture in a small scale culture, the method comprising:

• providing a 4-L to 10-L fed batch bioreactor containing a first culture medium that occupies between about 70% and about 90% of the capacity of the bioreactor and has an initial cell density of between about 2.5×105 and about 7.5×105 NS0 cells/mL, the cells comprising a recombinant eculizumab-encoding nucleic acid;
• culturing the cells in the bioreactor for at least 8 days at about 34° C. to about 39° C., at a dO2 level of between about 14% to about 16%, and a rotary agitation of between about 50 RPM and about 70 RPM;
• maintaining fed batch culturing until a cell density of about 13×105 to about 20×105 cells/mL is reached, then;
• (1) continuously adding a feed culture medium to the first culture medium for a period of about 120 hours to about 150 hours, and about 40 to 60 hours after the start of continuous addition of the feed culture medium, and
• (2) continuously adding an alkali base solution to the first culture medium for a period of between about 90 hours to about 105 hours.