Basic Principle of Ion Exchange Chromatography (IEX)
Biomolecules are structurally complex with multiple charges, making them an ideal candidate for ion exchange chromatography. Ion exchange—chromatography separates based on ionic charge. Molecules are typically eluted with a salt gradient, although elution with a pH gradient is possible. When eluting with a salt gradient, the charged salt ions and the molecule of interest compete for binding to the oppositely charged functional groups on the stationary phase. When using a salt gradient without organic solvent, IEX chromatography is a non-denaturing technique.
