Monday, 15 April 2013

Affinity Chromatography - Type of Liquid Chromatography

One of the most powerful chromatographic separation is done by the affinity method also called as an Affinity chromatography. It is a method which is used in analytical chemistry and is used to separate and purify the biological molecule from the given mixture which is based on the attraction on the molecule to the particular ligand which is being previously attached to the solid, inert substance.

Let us see the simple explanation of this affinity chromatography method:
The entire process is very simple so let us check it out with simple example: Suppose if the mixture of proteins or nucleic acids (molecules) is present, then it is passed through a column which contains a component known as  ligand which is present on the stationary substance. Now the molecule or protein is passed through this column , during this process some of the  molecule or component binds to the ligand due to their high affinity (which means they fit to the ligand like lock and key), while some the component will not bind entirely with the ligand and are eliminated by washing it out. Now the molecule which binds with the ligand needs to be detach from each other, so how to detach it? So in order to achieve our goal special chemical is flushed through the column  and this will detach the mixture of specific proteins with the given ligands and in this way specific proteins, molecules, nucleic acids etc are separated by this affinity chromatography method.
Uses of Affinity Chromatography

  1. Use to separate biochemical mixtures based on interaction between antigen and antibody, enzyme and substrate or by receptor and ligands.
  2. Used to purify and concentrate enzyme solutions.
  3. Purify and concentrate a substance or component from a mixture into buffering solution.