What is Gel filtration?
Gel filtration (GF) is a chromatography technique that separates molecules according to size. Within the fractionation range chosen, molecules are eluted in order of decreasing size. The separation mechanism is non-adsorptive and independent on the eluent system used and thus very gentle. Recoveries are very high both on the basis of mass and biological activity. Since GF is non-adsorptive and eluted under isocratic conditions (no gradients or steps) the sample is not concentrated during the separation, but slightly diluted, a fact that limits the applicable sample volume. The fact that the separation depends solely on molecular size makes the selectivity unique and high overall resolutions are obtained when gel filtration is combined with other LC techniques. Since large molecules elute earlier than small ones, proteins and peptides will elute in the buffer used to equilibrate the gel filtration column, regardless of the original sample solvent. GF can thus be used for desalting, buff
