Purified proteins and process therefor

Homogeneous proteins having molecular weights greater than 12,000, e.g. interferon, and a process for the purification of such proteins which process comprises passing an aqueous solution of said protein in an impure state through a buffer equilibrated column of a modified porous silica matrix under high performance liquid chromatography conditions and eluting said protein with an increasing or decreasing gradient of an aqueous water miscible solvent.