Gel Filtration Chromatography

Gel filtration chromatography does not involve bind–elute chromatography but rather separates proteins on the basis of size through porous beads. Large molecules are not able to enter the pores and elute first whereas small molecules elute later. In order for gel filtration chromatography to separate entirely on the basis of size alone, there must be no interaction between the matrix and the molecules in the mobile phase.
Gel filtration chromatography has been used for over 50 years and is primarily used as a polishing step late in downstream processing where the feedstream is relatively pure compared with earlier purification steps.
Gel filtration is mainly used at the industrial scale as a final chromatography step to remove protein aggregates and small impurities and has a low loading capacity and low throughput. A vast array of different columns and matrices are now commercially available with pore sizes as
small as 3 mm. The majority of the developments in the use of gel filtration in recent years have been in its utilisation as an analytical tool and for the separation of biopolymers rather than proteins, especially at an industrial scale.