Affinity chromatography is used to isolate a single compound from a complex mixture. When a sample passes through the affinity column, a certain compound specifically binds to the stationary phase. All unwanted material is washed through, leaving the one solute bound to the column. To elute the target solute, the conditions of the column, such as pH or ionic strength, can be changed to weaken the solute's binding. Diagrams on the basic process of affinity chromatography can be found on the Affinity Chromatography Website.
Biochemists frequently use affinity chromatography for protein purification. This process is based on specific interactions between enzymes and substrates, antibodies and antigens, or receptors and hormones. Aiding these interactions is packing material, called the affinity matrix, that must be inert and easily modified. In biological labs, agarose is the most common substance used, in spite of its cost. To find more about how affinity chromatography is applied in the lab, link to Affinity Chromatography, the Works!
Because of its large association with proteins, affinity chromatography contributes to the advancing field of gentics. In the article Using a biochemical approach to identify the primary dimerization regions in human DNA topoisomerase II.alpha, Lotte Bjergbaek, Sanne Jensen, Ole Westergaard, and Anni H. Andersen describe how affinity chromatography is used to study DNA metabolism and chromosome dynamics.
I the article, Affinity chromatography: a review of clinical applications, David S. Hage, carefully reviews the importance of affinity chromatography in clinical studies. These articles can be found in J. Biological Chemistry 274, no. 37 and Clinical Chemistry 45 no. 5, respectively.
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