A method of modifying the binding properties on a surface of a solid phase on which there are nucleophilic groups, which is characterized in that the surface is treated with a solution of an activated polysaccharide; a method of immobilizing a chemical compound to a solid phase on which there are immobilized activated polysaccharides, whereby the chemical compound is contacted with the surface of the solid phase the binding properties of which are modified by the method according to the invention; an article which is characterized in that to the surface thereof an activated polysaccharide is fixated, such as activated dextran or activated agarose, and use of this article for use in solid phase reactions, in solid phase assay, solid phase peptide synthesis, solid phase nucleotide synthesis, solid phase enzyme processing, and joining of biological surfaces.