A compact table-top centrifige with flow-through tubing for sample load and solvent flow.  Donut shaped high density PE rings hold a MW cut-off membrane that divides the spiral flow channel.  Upper channel sample flow and lower channel is gradient of salt or solvent that causes precipitation of analytes according to precipitation point and their separation in the centrifugal force field.  Proteins or nano-compounds can be isolated out of complex solutions and collected at end in fraction collector.  More information forthcoming  with references on uses for immunology characterization, protein/enzyme purifications in one-step from extracts and DNA plasmid isolation.