Purification of human fibroblast interferon by zinc chelate affinity chromatography.

Zinc chelated by iminodiacetic acid linked to an insoluble matrix binds human fibroblast interferon quite selectively at neutral pH in 0.15 M NaCL. On reduction of the pH and increase of the ionic strength, the interferon is eluted. Using a pH gradient at constant high ionic strength, good purification of the interferon can be obtained, up to a final specific activity of 108.5 units/mg of protein. Approximately 60% of the applied activity can be recovered.