What type of chromatography takes advantage of non-covalent interactions for protein purification?

Affinity chromatography is a powerful technique used for protein purification that relies on specific non-covalent interactions between the target protein and a ligand that is immobilized on a chromatography matrix. This method capitalizes on the unique binding properties of proteins, such as their ability to interact with antibodies, enzymes, nucleic acids, or other biomolecules.

In affinity chromatography, the protein mixture is passed through a column containing the immobilized ligand. Only the protein that specifically binds to the ligand will be retained in the column, while other proteins can be washed away. Afterward, the bound protein can be eluted by adding a solution that competes with the binding interaction, often by altering the conditions (such as pH or salt concentration) or by using a solution containing a high concentration of the free ligand. This technique allows for a high degree of purification and can yield proteins in their functional state due to the non-covalent nature of the interactions involved, minimizing potential alterations to their structure.

The other chromatography methods have different operational principles. Ionic chromatography involves separation based on charge interactions, size exclusion chromatography separates molecules based on their size, and gas chromatography is used primarily for volatile substances and not suitable for proteins. Each method serves distinct purposes in biochemical applications, but affinity