Centrifugation of mammalian cells is the operation most commonly used  as the first step in the recovery of recombinant glycoproteins. However, large-scale centrifugation equipment is expensive and undesirable cell damage can occur under this operation.  Accordingly, in this work the use of flocculants as studied as an alternative to centrifugation for the initial clarification of two different model recombinant glycoproteins, erythropoietin and a monoclonal antibody, from Chinnese Hamster Ovary (CHO) cells. Ten different polymers, including poly-L-amino acids, polyacrylamide co-polymers and polyamides, were evaluated at concentrations between 60 to 100 ppm.  The effect on cell viability, sedimentation rate and clarification efficiency was evaluated.  The best clarification resulted when using polyethylenimine, whose effect on the glycosilation pattern (quality) of recovered glycoprotein was studied. Whereas no effect on the quality and interaction (as determined by dynamic light scattering) of the recovered recombinant monoclonal antibody was observed, polyethylenimine had a negative effect on the glycosylation pattern of recombinant erythropoietin. In particular, the flocculant removed highsialic acid glycoforms, and thus, affected the quality of the final product. The results that will be presented will show the cases and conditions where flocculants can successfully replace centrifugation as the first clarification step in production of recombinant glycoproteins and will also show the cases and conditions were flocculation is undesirable.  To our knowledge, this is the first report of how flocculants can affect the glycosylation profiles of recovered recombinant glycoproteins.

Flocculation of CHO cells for separation of recombinant glycoproteins: Effect on glycosylation profiles

243rd National Meeting (2012)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.