Comparison of Cationic Flocculants for the Clarification of CHO-derived Monoclonal Antibodies

This work used two different cationic polyelectrolytes as flocculation agents for the clarification of growth medium from Chinese hamster ovary (CHO) monoclonal antibodies (mAb)-producing cells, namely chitosan and poly diallyldimethylammonium chloride (pDADMAC). The conditions set for the use of pDADMAC consisted in the variation of the polymer’s concentrations, in light of largely available literature. Chitosan was applied to a broader concentration-range under two different pH values, for its use in CHO cells flocculation is unprecedented in the literature. Chitosan presented the best performance on clarification assays under a concentration 9-fold lower compared with pDADMAC (5 pg/total cell (TC) and 45 pg/TC, respectively), albeit both agents provided similar results regarding sedimentation rates (15 min), DNA removal (98%), and mAb recovery (90%). Despite the expected low proteins removal, namely 11.1% in the case of chitosan and no removal for pDADMAC, the flocculation technique proved to be cost-effective. Hence, its application can be envisioned not only when the clarification of a growth medium from CHO cells production is considered, but also for the removal of soluble impurities in a single step.