Affinity extractants for selective recovery of IgG from Proteins

Due to the required high purity and low concentrations in product streams from current cell lines, downstream processing represents the major part of the overall production costs for monoclonal antibodies. Extractive separations offer potential for significant cost reductions through process intensification compared to currently-applied chromatographic separations. This work presents a new methodology for the direct extraction of IgG into an apolar organic solvent (iso-octane). This methodology is based on the integration of affinity chromatography ligands into selective extractants with apolar tails. Experimental evaluation demonstrated that with the synthesised affinity extractants recovery of IgG, up to 70% can be achieved in one extraction step, while no extraction of proteins such as myoglobin (MYO) or human serum albumin (HSA) was observed. In mixtures of IgG with the myoglobin and real fermentation product the overall selectivity was reduced due to competitive interactions resulting in a decreased extraction of IgG.