Mj. Keen et Nt. Rapson, DEVELOPMENT OF A SERUM-FREE CULTURE-MEDIUM FOR THE LARGE-SCALE PRODUCTION OF RECOMBINANT PROTEIN FROM A CHINESE-HAMSTER OVARY CELL-LINE, Cytotechnology, 17(3), 1995, pp. 153-163
A serum-free medium, WCM5, has been developed for the large scale prop
agation of CHO (Chinese hamster ovary) cells which express recombinant
protein using dihydrofolate reductase as a selectable marker. WCM5 wa
s prepared by supplementing Iscoves medium without lecithin, albumin o
r transferrin with a number of components which were shown to benefit
growth. WCM5 medium contained 5 mg l(-1) human recombinant insulin (Nu
cellin) but was otherwise protein-free. CHO 3D11 cells which had been
engineered to express a humanised antibody, CAMPATH-1H, were routine
ly grown using serum-containing medium. From a seeding density of 10(5
) cells ml(-1), cells grown in static culture with serum reached a max
imal cell density of 6.5 x 10(5) cells ml(-1) after 6 days in culture
and produced a maximal antibody concentration of 69 mg l(-1) after 11
days in culture. CHO 3D11 cells grown with serum were washed in serum
-free medium then cultured in WCM5 medium. Following a period of adapt
ation the cell growth and product yield was superior to that achieved
with serum-containing medium. CHO cells producing CAMPATH-1H grown in
an 8000 l stirred bioreactor seeded with 2 x 10(5) cells ml(-1) reache
d a maximal viable cell density of 2.16 x 10(6) cells ml(-1) after 108
h in culture and a maximal antibody concentration of 131.1 mg l(-1) a
fter 122 h in culture.