Muller, N.Derouazi, M.Van Tilborgh, F.Wulhfard, S.Hacker, D. L.Jordan, M.Wurm, F. M.2007-07-202007-07-202007-07-20200710.1007/s10529-006-9298-xhttps://infoscience.epfl.ch/handle/20.500.14299/9754WOS:00024551980000417310326Cell expansion, gene transfer and protein production were all executed with a single serum-free, animal protein-free commercial medium designed for suspension-adapted Chinese hamster ovary cells (CHO DG44). This is a most important process to consider for clinical production of recombinant proteins. The transfection with polyethylenimine (PEI) was shown here to be scalable using both stirred-tank bioreactors of 3- and 150-l and novel agitated cultivation vessels (50 ml ventilated centrifuge tubes and 1-l square-shaped glass bottles) that lack any instrumentation. The transient transfections spanned a range of working volumes from 2 ml to 80 l. The maximum transient recombinant antibody yield was 22 mg/l, the highest ever reported for a multiliter transfection in CHO. The transiently expressed protein had the same extent of glycosylation as the same antibody produced from a stably transfected recombinant CHO cell line.text::journal::journal article::research article