Size exclusion chromatography
Size-exclusion chromatography (SEC) is a chromatographic
Chromatography is the collective term for a set of laboratory techniques for the separation of mixtures....

 method in which molecules in solution are separated by their size, and in some cases molecular weight . It is usually applied to large molecule
A molecule is an electrically neutral group of at least two atoms held together by covalent chemical bonds. Molecules are distinguished from ions by their electrical charge...

s or macromolecular complexes such as proteins and industrial polymers. Typically, when an aqueous solution is used to transport the sample through the column, the technique is known as gel-filtration chromatography, versus the name Gel permeation chromatography
Gel Permeation Chromatography
Gel permeation chromatography is a type of size exclusion chromatography , that separates analytes on the basis of size. The technique is often used for the analysis of polymers. As a technique, SEC was first developed in 1955 by Lathe and Ruthven. The term gel permeation chromatography can be...

, which is used when an organic solvent is used as a mobile phase.