An exclusion mechanism in ion exchange chromatography
Article first published online: 8 AUG 2006
Copyright © 2006 Wiley Periodicals, Inc.
Biotechnology and Bioengineering
Volume 95, Issue 5, pages 775–787, 5 December 2006
How to Cite
Harinarayan, C., Mueller, J., Ljunglöf, A., Fahrner, R., Van Alstine, J. and van Reis, R. (2006), An exclusion mechanism in ion exchange chromatography. Biotechnol. Bioeng., 95: 775–787. doi: 10.1002/bit.21080
- Issue published online: 25 OCT 2006
- Article first published online: 8 AUG 2006
- Manuscript Accepted: 13 JUN 2006
- Manuscript Received: 13 MAR 2006
- ion exchange chromatography;
- binding capacity;
- confocal microscopy
Protein dynamic binding capacities on ion exchange resins are typically expected to decrease with increasing conductivity and decreasing protein charge. There are, however, conditions where capacity increases with increasing conductivity and decreasing protein charge. Capacity measurements on two different commercial ion exchange resins with three different monoclonal antibodies at various pH and conductivities exhibited two domains. In the first domain, the capacity unexpectedly increased with increasing conductivity and decreasing protein charge. The second domain exhibited traditional behavior. A mechanism to explain the first domain is postulated; proteins initially bind to the outer pore regions and electrostatically hinder subsequent protein transport. Such a mechanism is supported by protein capacity and confocal microscopy studies whose results suggest how knowledge of the two types of IEX behavior can be leveraged in optimizing resins and processes. © 2006 Wiley Periodicals, Inc.