Size exclusion chromatography

Size exclusion chromatography is a type of liquid chromatography where the molecules in the sample are separated according to their size.

The stationary phase is normally a gel composed of spherical porous beads with a specific size distribution. Depending on the size of different molecules, they will be included or excluded from the pores within the beads. Those included in the pores will stay longer in the stationary phase before eluting, while those excluded will elute more rapidly as they will not be retained within the matrix. Therefore, smaller molecules will elute later than bigger ones (Figure 1).

Figure 1. Example of size exclusion chromatography.

The resolution of the chromatogram depends on a few factors.