Page "Gel permeation chromatography" Paragraph 10

Gels are used as stationary phase for GPC.

The pore size of a gel must be carefully controlled in order to be able to apply the gel to a given separation.

Other desirable properties of the gel forming agent are the absence of ionizing groups and, in a given solvent, low affinity for the substances to be separated.

Commercial gels like Sephadex, Bio-Gel ( cross-linked polyacrylamide ), agarose gel and Styragel are often used based on different separation requirements.