What is under layering and what are its benefits?
Instead of loading a tube with the densest gradient medium first, followed by layers of lighter media, the lightest medium is loaded first. Then the next densest medium is slowly added to the bottom of the tube, floating the lighter medium. The advantage, if done properly, is much sharper bands of the discontinuous gradient. The benefit will be higher yields and greater purities in a rate zonal and barrier techniques.
