Affinity Chromatography

  This type of chromatography involves binding a reagent to the analyte molecules in a sample. After the binding, only the molecules that have this ligand are retained in the column, the unbound analyte is passed through in the mobile phase. The stationary phase is usually agrose or a porous glass bead that is able to immobilize the bonded molecule. It is possible to change the elution conditions by manipulating the pH or the ionic strength of the binding ligand. This method is often used in biochemistry in the purification of proteins. The ligand tag is bonded and after separation the tag is then removed and the and the pure protein is obtained.