Results demonstrated that for the recombinant CHO cell line studied, the addition of chemically defined feed to the basal
medium produced approximately a four-fold greater protein yield than any of the four different plant hydrolysates used. Also,
culture supplementation with different plant hydrolysates in combination with chemically defined feeds provided no advantage
in terms of increased protein production over the addition of a chemically defined feed on its own. Supplementing media with
plant hydrolysates may not always be the most efficient choice or may not offer the same increases in productivity available
from chemically defined feeds. Therefore, when culturing CHO cells for maximum protein production, it may be worthwhile to
compare different feed types. Bioreactor studies of a different CHO cell line also demonstrated that chemically defined feeds
in the culture provided slightly higher protein yields than the addition of a soy hydrolysate when the two feeds were added
at the same concentration. In addition, using a higher concentration of chemically defined feed A on day 0 followed by feed
B on day 6 yielded superior bioproductivity and proved the value of including multiple, and sometimes counter-intuitive, feeding
strategies when trying to maximize protein production.
In summary, using chemically defined feeds with CHO cell lines not only eliminates the variability associated with using plant
hydrolysates, but could also improve the productivity of biopharmaceutical protein manufacture and help move therapeutic proteins
into clinical trials more rapidly.
David (Xiaojian) Zhao is a technical area manager of media development, Richard Fike is a principal scientist, Cell Systems Division, Borka Naumovich is an associate scientist III, and Mark Stramaglia is a senior product manager, all at Invitrogen Corporation, Grand Island, NY, 716.774.6860, email@example.com
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