Countercurrent chromatography (CCC) of proteins was performed by the cross-axis coil planet centrifuge (cross-axis CPC) using polyethylene glycol (PEG) - dextran biphasic systems. A pair of eccentric coil assemblies was mounted at two different positions (off-center and central) on the rotary frame. The best separation was obtained from a two-phase solvent system composed of 4.0% (w/w) PEG 8000 - 5.0% (w/w) dextran T500 in 5 mM potassium phosphate buffer (pH 7.0) and 3 M sodium chloride using the upper PEG-rich phase as the mobile phase. The off-center column position yielded substantially better peak resolution between lysozyme and myoglobin than that obtained from the central position under otherwise identical conditions.