The setup is relatively simple. We have this funnel, and we place the funnel on top of this long column. And inside the column, we have these gel beads. Now, what's so special about these spherical gel beads? Well, these gel beads consist of a hydrated polymer, such as, for example, dexterin, which is a carbohydrate. And even though this molecule, this bead, is insoluble, it doesn't dissolve in aqueous solutions.