Results of a novel method of covalent bonding of an antibiotic (gentamicin) to silica bead supports are shown. Gentamicin was immobilized to four types of matrix: silica gel and porous glass beads activated by either silanization (APTES) or by adhesively bound keratin (with immobilization yield ranging from 36.5 to 91%). Gentamicin was immobilized to the supports after opening its carbohydrate ring in the molecule. This method of gentamicin activation before the immobilization process did not inhibit its antibiotic activity. The four gentamicin-containing immobilized preparations were stable, meaning that they did not release the antibiotic into the solution during the 30 days of incubation, not even during shaking experiments.