In the affinity chromatography, the proteins are separated as per the dissimilarity in their binding affinity. There is a high binding affinity for specific ligands in enzymes, antibodies, and receptors.
While the protein mixture is passed by a column which is composed with a material of legend coupled matrix, just proteins that bind the ligand can be retained. The target protein is eluted from the column by a solution, which competes for the target of the protein binding, i.e. the ligand.
The principle of affinity chromatography is as follows:
1. Initially inject a sample into an equilibrated column of affinity chromatography.
2. The substance in which there is an affinity to the ligand, only that substance retained in the column.
3. The substance is eluted from the column in which there is no affinity to the ligand.
4. By modifying the salt or organic solvent concentrations or pH, retained substances can be eluted from the column.Affinity chromatography is broadly used for the separation and purification with the specific properties.
References
A. Wikipedia: https://en.wikipedia.org/wiki/High-performance_liquid_chromatography
B. Knauer: https://www.knauer.net/en/search?q=chromatography
C. Kromasil: https://www.kromasil.com/support/faq.php
D. Shimadzu: https://www.shimadzu.com/an/service-support/technical-support/analysis-basics/basic/what_is_hplc.html
E. ChemistryView: https://www.chemistryviews.org/details/education/9464911/What_is_HPLC/