Selection of pH-related parameters in ion-exchange chromatography using pH-gradient operations

This work demonstrates that the type of ion-exchanger (anion or cation), the mode of operation (bind-and-elute or flow-through), and the operational pH of ion-exchange chromatography (IEX) can be selected in a fast and rational way by analytical pH-gradient IEX operations, thereby eliminating the need for pH scouting or high-throughput screening. The developed approach was applied for the selection of an IEX process for the capture of a monoclonal antibody (MAb) from hybridoma cell culture supernatant (CCS). It was found within a day that MAb can optimally be captured by bind-and-elute mode cation-exchange chromatography (CEX) at pH 4.5 or anion-exchange chromatography (AEX) at pH 7.2 without lowering the salt concentration in the CCS. The performance of both CEX and AEX was predicted to be equal for this particular MAb capture.