A continuous rod of porous poly(glycidyl methacrylate-co-ethylene dimethacrylate) has been prepared by a free radical polymerization within the confines of a 16-mm-i.d. glass column. The epoxide groups of the rod have been modified in situ by their reaction with diethylamine to afford the ionizable weak base 1-N,N-diethylamino-2-hydroxypropyl functionalities that are required for the ion-exchange chromatographic mode. The bimodal pore size distribution curve typical for other molded separation media also prevail for the preparative-size rod. The column has been used successfully for the chromatographic separation of a mixture of standard proteins and yeast enzymes. The column exhibits a dynamic capacity that exceeds 420 mg of bovine serum albumin at a flow velocity of 60 cm/h.