Salt-enhanced permeabilization for monoclonal antibody precipitation and purification in a tubular reactor with a depth filtration membrane with advanced chromatin extraction

Non-protein A-based purification technology is increasingly needed in that protein A chromatography possesses mang inherent problems, such as the high material and operational costs, limited productivity, and leaching of the protein A ligand. In this study, antibody purification was first achieved by precipitation of the antibody from the cell culture supernatant (CCS) in a tubular reactor with a static mixer. The protein precipitates were efficiently intercepted by incorporating a depth filtration membrane directly after the mixer. Chromatin-directed cell culture clarification was shown to enable the full usage of the load of the filter membrane and also significantly reduced the burden of the subsequent purification step. The addition of NaCl to the CCS significantly increased the permeabilization of the filter membrane by increasing the loading capacity by up to 20%. The re-dissolved and eluted antibodies were further polished using single multimodal chromatography, which supported direct sample loading. The content of non-histone host cell protein (n-h-HCP) in the final product was less than 20 ppm, DNA was less than 1 ppb, and the aggregates was less than 0.05%. The overall antibody recovery was ˜82%. This method is a feasible alternative to the current protein A-dominant antibody purification platform and has high value and potential for widespread implementation.