The apparatus holds a set of four identical multilayer coils around the column holder. These columns are interconnected in series to make up a total capacity of about 200ml. Because of the eccentric orientation of the multilayer coils with respect to the axis of the holder, the radially acting centrifugal force from the holder axis retains the stationary phase, either the lighter or the heavier phase, in each helical turn of the coil while the planetary motion of the coil produces efficient mixing of the two solvent phases. The system provides universal application of two-phase solvent systems including aqueous-aqueous polymer phase systems used for partition of macromolecules and cell particles. The capability of the apparatus was successfully demonstrated in separation of cytochrome c and lysozyme in a polymer phase system composed of 12.5% polyethylene glycol 1000 in IM potassium phosphate aqueous solution.