Stress-free chromatography: IEC and HIC

Ion exchange chromatography (IEC) poses stresses on proteins in both binding and elution steps. Proteins often bind to the column with high affinity, resulting in concentration of the protein upon binding. Elution often requires high salt concentration, leading to high protein concentration with high salt concentration. Although hydrophobic interaction chromatography (HIC) involves weak interaction, salting-out salts are used for binding. These conditions may cause protein aggregation. This short article describes an approach to reduce such aggregation in IEC and HIC. This was achieved by adding small amount of salt or arginine in the loading sample or elution solvent, resulting in elution of proteins with less aggregation or higher recovery.