AFFINITY CHROMATOGRAPHY...THE WORKS !
An intriguing chromatographic technique based on the natural specificity of some biopolymers is affinity chromatography.
There are a number of proteins and other biological macromolecules that complex with some other biological entity with a high degree of specificity. This fact is made use of in product recovery operations via the use of affinity chromatography.
Suppose a certain biomolecule (a) is attached to a solid used to pack a chromatographic column. Now consider a molecule (b) in solution, which has a specific affinity for (a). It is but natural that (b) will want to get out of solution and bind to (a), right? It's this attraction of (b) for (a) which is defined as the partition coefficient 'K'. Now since 'K' for (b) is going to be much higher than that of any other proteins in solution, it will bind to the column while the rest of the complex solution will merely pass through the column with insignificant amounts of non-specific binding occuring.
What are some examples of molecules which may be used for this technique?
ENZYME + INHIBITOR <=> ENZYME-INHIBITOR COMPLEX
ANTIBODY + ANTIGEN ---> ANTIBODY-ANTIGEN PRECIPITATE
LECTIN + CELL WALL -----> LECTIN-CELL-WALL COMPLEX