An analytical technique used to separate molecules based on how they tend to cling to or dissolve in various solids, liquids and gases: column chromatography is used most often to separate proteins based on their binding to a column lined with a ligand specific to a certain protein. gel filtration chromatography is used most often to separate proteins by running the solution containing the proteins through a column filled with porous carbohydrate gel beads which will trap or slow down small molecules but will allow larger molecules to slide past. paper chromatography separates molecules by taking advantage of their differing solubilities in a mix of solvents. The material to be separated is applied to a special piece of paper, and the edge of the paper is put in the solvent mix, which travels through the paper by capillary action and carries the different molecules at different rates with it.