Ion exchange chromatography is a chromatography method that separates substances according to the difference in charge properties of different biomolecules. The ion exchange chromatography medium is composed of agarose/dextran/polymer matrix coupled with ligands with positive and negative charges. The medium with negative charge is called cation exchange chromatography medium, which can bind positively charged proteins; the medium with negative charge is called anion exchange chromatography medium, which can bind negatively charged proteins.