Affinity chromatography is a chromatographic technique that uses the specific affinity between biomolecules for separation. Specifically, affinity chromatography involves immobilizing a ligand on an inert carrier, and the target protein in the mixture is specifically bound to the ligand and thus captured, while the extraneous impurity components are washed off with the mobile phase, and then a suitable eluent is selected to elute the target protein from the carrier, resulting in a single component of purified material. Learn more: Difference Between Protein A/G/L