A method of making a derivatized aminoglycoside includes reacting an aminoglycoside with at least 2 equivalents of a divalent metal ion in an aprotic solvent to complex two neighboring amino group and hydroxyl group pairs; reacting the non-complexed amino groups with a protecting reagent to provide protecting groups; removing the divalent metal ion to provide two unprotected amino groups; reacting one of the unprotected amino groups with a reactive substance containing an linker, a carrier, or a label; and removing the protecting groups. This method can be used to produce novel compounds and reagents.