Affinity Chromatography
All molecules, particularly proteins, have a complex three dimensional structure. Ligands that have the ability to recognize one of the structural motifs of a molecule are used in what is called affinity chromatography. This interaction can be extremely specific and the ligand will interact with only one type of molecule, or the ligand can be designed so that it recognizes a group of structurally similar molecules.

Ideally the ligand on the solid support should have excellent avidity to the target molecule. However, it is possible to have too much of a good thing. If the adsorption is too strong it will make it too difficult to desorb the target from the column.

If the affinity ligand is a peptide or protein, special care must be taken so that its structure is maintained throughout the purification process. 

Purification and Analysis
Since affinity chromatography is so selective, it is a very powerful tool in isolating and purifying proteins from a complex feedstream. The most well-known application of affinity chromatography is as a capture step in the purification of monoclonal antibody-based pharmaceuticals. Athough affinity chromatography is also used as an analytical technique, it has not reached the same popularity as in process chromatography.

Find out more

• TSKgel affinity columns (HPLC and FPLC)
• Toyopearl and TSKgel affinity resins