ABSTRACT
Affinity chromatography usually is defined as the purification of a molecule based on its specific retention by a second, immobilized molecule. Affinity separations may be based on the interactions of peptides with proteins, saccharides with proteins, proteins with proteins, and nucleic acids with proteins or other nucleic acids. Immobilized metal affinity chromatography was introduced by J. Porath et al. Chelation usually is by iminodiacetic acid coupled to polysaccharide or silica supports. Purification fusions are sequences or regions of other proteins added to the protein of interest. Fusions may confer immunoaffinity, substrate affinity, metal chelation, or high charge density. The preponderance of industrial-scale affinity separations is with beaded agarose matrices. The emergence of microporous glass as an affinity matrix coincided with the recruitment of Howard Weetall by the Corning Glass Works. Weetall had studied affinity systems at CalTech with Dan Campbell’s group and was a collaborator of Ralph Messing at NASA.
