The present invention relates to a method of preparing a porous cross-linked polysaccharide chromatography matrix, which comprises to provide an aqueous solution of a gellable polysaccharide, wherein part of the hydroxyl groups are substituted with groups which are not susceptible to nucleophilic attack; to provide essentially spherical droplets of the substituted polysaccharide solution; to form a gel of the substituted polysaccharide solution; and to cross-link the gel by adding a cross-linking agent. The invention also encompasses a chromatography column packed with a matrix so produced as well as use thereof in e.g. protein purification.