Principles of Biochemistry (2+1)

5.3.2.2.2.2 Ion-exchange chromatography

Ion-exchange chromatography refers to separation of proteins based on charge. Columns can either be prepared for anion exchange or cation exchange. Anion exchange columns contain a stationary phase with a positive charge that attracts negatively charged proteins. Cation exchange columns are the reverse, negatively charged beads which attract positively charged proteins. Elution of the target protein(s) is done by changing the pH in the column, which results in a change or neutralization of the charged functional groups of each protein.