This work describes automated chromatographic methods for the separation of medically useful radionuclides from source material containing their parent radionuclides. The separation techniques employ two chromatographic columns to ensure high chemical and radiochemical purity of the product radionuclide. The separations were performed using an automated system, the automated radionuclide separator (ARS2), consisting of syringe pumps and multiport valves controlled through a computer interface. Generator systems for (68)Ga, (99m)Tc, (188)Re and (213)Bi will be described.