Effect of Chitosan and pH on Clarification Process Efficiency of Harvested CHO Cell Culture Fluid

Abstract:

Chitosan is a natural，non-toxic and biodegradable flocculant. This study focused on determining and optimizing the clarification process efficiency in the presence of various concentrations （0~ 0.10 g/dL） of chitosan at different pH 5.0~7.0 for the harvested Chinese hamster ovary （CHO） cell culture fluid （HCCF）（pH 7.0）. Following HCCF was treated with 0.06 g/dL chitosan，the filtration flux was achieved up to 8 266.22 L/（m2·h） using 0.22 μm filter. In addition，the result showed that similar filtration flux for HCCF at different pH without chitosan addition whereas increasing filtration flux was achieved when HCCF pre-treated with chitosan at decreasing pH. To further improve this clarification process，the combined effect of various concentrations of chitosan at different pH on the filtration flux and the removal of process impurities including host cell proteins （HCP） and residual DNA in HCCF was evaluated. The result of a full factorial experiment including two factors and three levels （chitosan at 0.02，0.04，0.06% and pH at 5，6，7） showed that 90% antibody product yield with nearly complete removal of residual DNA and 50% more reduction of HCP were obtained when HCCF pre-treated with the optimal 0.06 g/dL chitosan at pH 5.0.