Abstract: The invention relates to a process for the immobilization of compounds comprising nucleophilic groups.According to the process of the invention a polymer comprising an amido group is swollen in a buffer. For this purpose any buffer is suitable which contains no amino, sulfhydryl and/or hydroxy groups in the molecule. To the swollen polymer a solution of a quinone - preferably p-benzoquinone - in a water miscible organic solvent is added and the mixture is activated at 273.degree.-343.degree. K. for 0.5-48 hours - preferably for 24 hours. The unreacted quinone is washed out with an aqueous solution of a water miscible organic solvent and thereafter water and/or a buffer. To the purified gel at a pH value between 3 and 11 - preferably between 6 and 8 - a buffered solution of a compound comprising a nucleophilic group is added, the suspension is incubated at 260.degree.-313.degree. K. for 24 hours, the gel is separated and the non-bound compound comprising a nucleophilic group is removed by washing.