Analytical techniques for cell fractions

A simple gradient device is described which allows convex gradients to be formed for use in zonal centrifuge rotors. The configuration chosen produces very rapid mixing of the very viscous sucrose solutions. By varying the total volume of the mixer, the shape of the gradient may be altered within rather wide limits. With large volume mixers, gradients may be obtained which are very nearly linear with radius when placed in the sector-shaped compartments of the rotor. With smaller volume mixers, gradients that are convex with respect to radius when in position in the rotor may be generated which are more useful where high-capacity high-resolution separations are required.