CGE uses separation based on the difference in solute size as the particles migrate through the gel. Gels are useful because they minimize solute diffusion that causes zone broadening, prevent the capillary walls from absorbing the solute, and limit the heat transfer by slowing down the molecules.  A commonly used gel apparatus for the separation of proteins is capillary SDS-PAGE.  It is a highly sensitive system and only requires a small amount of sample.

BiOptic's CGE technology is a vertical electrophoresis system with a novel fluorescence detection: