• Affinity Chromatography:
• powerful liquid chromatographic purification technique that separates biological molecules based on highly specific, reversible, non-covalent biological binding interactions.
• specific ligand (e.g., antibody, enzyme substrate, hormone, nucleic acid, histidine-tag binding nickel chelate) is immobilized onto an insoluble chromatographic matrix (agarose/Sepharose).
• Only the target molecule possessing binding affinity binds to the stationary column, while unbound contaminants are washed away. The target is subsequently eluted using a competitive ligand or altered pH/salt.
• nalysis:
• (Separate specific molecules based on a unique binding interaction): Correct.

Correct option: (2) Separate specific molecules based on a unique binding interaction