The principle of affinity chromatography is as follows:
1) Inject a sample into an initially equilibrated affinity chromatography column(AFpak).
2) Only the substances with affinity for the ligand are retained in the column.
3) Other substances with no affinity for the ligand are eluted from the column.
4) The substances retained in the column can be eluted from the column by changing pH or salt or organic solvent concentration of the eluent.
Affinity chromatography is widely used as a means of separation and purification with specific properties.