The extremely rapid growth in the field of protein chemistry during the past 50 years has been due in large part to the development of very effective techniques of protein separation and analysis. A number of techniques such as electrophoresis or isoelectric focusing, based on the overall charge and mass of a biomolecule, have been widely applied. However, preparative isolation of proteins often involves some form of chromatography. The two modes of chromatography that have been most widely accepted and used for separation of biomolecules are partition chromatography and adsorption chromatography which includes affinity chromatography. The technique of affinity chromatography exploits the unique biological specificity inherent in a ligand-macro-molecule interaction. Thus, among separation procedures, a group of methods based on the molecular affinities found in biological systems have become increasingly important.