Introduction Large-scale purification of MAbs usually consists of three chromatographic steps. Higher titers and higher feed volumes have created a demand on enhanced capacity and speed in the downstream processes. The most significant improvement thus far has been increased expression levels. MAbs are among the world s most expensive drugs and there is market pressure to decrease manufacturing costs considerably. Antibody-based therapeutics are expected to continue to be a major source of new therapies for the next decade. A cost analysis revealed that Capto Q is more economical than membranes when used in production and that the process economy of Capto Q increases with batch size and process frequency. Capto Q showed significantly higher HCP capacity than did membranes. The dynamic capacity of Capto Q for host cell proteins (HCP) and DNA was investigated and compared with other chromatography media and membranes. In this study, the reduction of contaminants (host cell proteins and Protein A) was evaluated using Capto Q in process purifications. Polishing is typically the last step in the purification process after Protein A and cationic exchange chromatography. 1 GE Healthcare Life Sciences Application note AB Ion exchange chromatography Process-scale purification of monoclonal antibodies polishing using Capto Q Summary Anionic exchange media are an industry standard for largescale polishing of monoclonal antibodies (MAbs).