Antibody Purification

Monoclonal antibodies are an important segment of the biopharmaceutical industry. Seven out of the 15 best-selling drugs are monoclonal antibodies.  Within the protein-based drugs, they are the market leader in terms of sales and annual revenues. Almost all therapeutic antibodies are produced by mammalian cell culture and downstream processing is used to produce a safe and highly purified product for human therapeutic applications.

Cell culture productivity has improved over the last decade, concentrations of 1-5 grams of antibody per liters of cell culture is typical. Chromatography is the workhorse of downstream processing due to its high resolution and reproducibility using simple with bind-wash-elute cycles.  Initial recovery is the critical step in determining the economy of a downstream process. The protein of interest needs to be efficiently captured and a majority of the impurities removed to increase the efficiency of further downstream. Protein A affinity resins typically represent the first step of monoclonal antibody purification.

Protein A resin provides an excellent concentration step, and typically removes 95-98% of the contaminating DNA, CHOP, virus and small molecules. Further purification and virus removal are achieved by adding polishing steps consisting of ion exchange and HIC resins.
Clarification of the feed stream can become a bottleneck in harvesting monoclonal antibodies from a fermentation broth. By selecting our Direct Capture CellthruTM resins, the purification process complexity is reduced and yield is improved.  In the current downstream process, cells are lysed under high sheer conditions resulting in contamination with DNA, CHOP, and other cellular components. Using our Protein A Cellthru™ Direct Capture™ resin, the protein of interest is bound under low shear conditions with a decreased level of contamination by cellular components.
Chelating affinity chromatography, such as Chelating Superflow and IDA Chelating CellthruTM has been also used for the purification of monoclonal antibodies from cell culture supernatant and from Pichia pastoris. High selectivity and high purification factors can be achieved for IgG. The monoclonal antibodies can be eluted using mild conditions causing no loss of antigen binding capacity.