Size Exclusion Chromatography (SEC) is the dominant mode of separation for polymers.

It is based on the discrimination of individual sample components by the pores of the packing material. Large sample molecules cannot or can only partially penetrate the pores, whereas smaller molecules can access all or a larger number of pores. 

In SEC, large molecules elute from the column first, smaller molecules elute later, and the smallest molecules that can access all the pores elute last from the column. Size exclusion chromatography is the only mode of chromatography that does not involve interaction with a stationary phase by means of adsorption or partitioning of the solutes.

Particles prepared from organic polymers have traditionally been the most widely used packing materials for size-exclusion chromatography (SEC). The terms SEC, GFC (gel filtration chromatography) and GPC (gel permeation chromatography) all refer to the same chromatographic technique. In GFC an aqueous mobile phase is used, while an organic mobile phase is employed in GPC. The general term SEC covers both uses.

GFC is popular among biochemists for the isolation of protein fractions or for the removal of aggregates in a final polishing step in biotechnology production. GFC is also frequently used for desalting a (protein) sample solution, often to prepare the sample for elution by another chromatographic mode.

GPC plays an important role in the characterization of industrial organic-soluble polymers.

Protein

The TSKgel SW-type columns, first introduced in 1977, are the standard in gel filtration chromatography. GFC is popular among biochemists for the isolation of proteins, for the removal of aggregates, to desalt a protein sample, to separate nucleic acid fractions, or to characterize water-soluble polymers used in food products, paints, pharmaceutical preparations. 

TSKgel SW, SWXL and SuperSW columns are silica-based GFC columns optimized for the separation of proteins and nucleic acids using an aqueous buffer as mobile phase. A hydrophilic diol-type bonded phase shields the silica surface from interacting with protein samples. Three different pore sizes are available. 

Compared to competitive HPLC columns, SW-type columns contain more pore volume per unit column volume, which results in higher MW selectivity or better resolution. The TSKgel BioAssist DS column is designed for the desalting and buffer exchange of proteins and polynucleotides at semi-preparative scale.