ABSTRACT
Research background: Protein A affinity chromatography is a well-established method currently used in the pharmaceutical industry. However, the high costs usually associated with chromatographic separation of protein A and the difficulties in continuous operation make the investigation of alternative purification methods very important. Experimental approach: In this study, extraction/back-extraction and precipitation/dissolution methods were developed and optimised. They were compared with protein A and cation exchange chromatography separations in terms of yield of monoclonal antibody (mAb) and amount of residual impurities, such as DNA and host cell proteins, and amount of mAb aggregates. For a comprehensive comparison of the different methods, experiments were carried out with the same cell-free fermentation broth containing adalimumab. Results and conclusions: Protein A and cation exchange chromatographic separations resulted in high yield and purity of adalimumab. The precipitation-based process resulted in high yield but with lower purity. The extraction-based purification resulted in low yield and purity. Thus, the precipitation-based method proved to be more promising than the extraction-based method for direct purification of adalimumab from harvested cell culture fluid. Novelty and scientific contribution: Although alternative purification methods may offer the advantages of simplicity and low-cost operation, further significant improvements are required to compete with the performance of chromatographic separations of adalimumab from true fermentation broth.