A method of attaching an azide moiety to a biomolecule. The method entails contacting a biomolecule in a solution with an azide and an oxidizing agent, for a time and at a temperature wherein at least one azide moiety is covalently bonded to the biomolecule to yield an azidylated biomolecule. The method can be used to identify hydrophobic microenvironments in soluble proteins. Also, a method of attaching a reagent comprising an alkyne to a biomolecule. The method comprises reacting a biomolecule in a solution with an azide and a reagent comprising an alkyne, for a time and at a temperature wherein at least one reagent comprising an alkyne is covalently bonded to the biomolecule via triazole linkage.