Chromatography in which separation is based mainly on exclusion effects, such as differences in molecular size and/or shape or in charge. The term size-exclusion chromatography may also be used when separation is based on molecular size. The terms gel filtration and gel-permeation chromatography (GPC) were used earlier to describe this process when the stationary phase is a swollen gel. The term ion-exclusion chromatography is specifically used for the separation of ions in an aqueous phase.