Patent ID: 7291484

Claim:
A method for culturing cells, said cells being human embryonic retina (HER) cells immortalized by adenovirus E1 sequences and able to grow in suspension, the method comprising the steps of: a) determining at least once during the culturing of the cells the concentration of at least one medium component selected from the group consisting of glucose, glutamine, phosphate, leucine, serine, isoleucine, arginine, methionine and cystine, and b) adding components to the medium during the culturing of the cells at or prior to the depletion of at least one of the components of which the concentration was determined in step a), wherein the components added at least comprise glucose, glutamine, phosphate, leucine, serine, isoleucine, arginine, methionine and cystine, wherein components in step b) are added to an end concentration in mmoles/l of freshly added component per 10×10 6 cells/ml of between 4.0 and 8.0 for glucose, 0.47 and 0.93 for phosphate, 0.44 and 0.88 for leucine, 0.37 and 1.47 for serine, 0.33 and 0.67 for isoleucine, 0.31 and 0.61 for arginine, 0.15 and 0.31 for methionine, and 0.1 and 0.6 for cystine.