Cy5 azide is a labeling reagent ready for the use in Click Chemistry reaction which available as 10 mM solution in DMSO. For biomolecule labeling, the labeling reagent has low aqueous solubility, using of organic co-solvent to dissolve this molecular is necessary for efficient reaction. First, Cyanine dye should be dissolved in organic solvent and then added to a solution of biomolecule in appropriate aqueous buffer. Alkyne-modified biomolecules in mixtures of water with organic solvents can be labeled by Cy5 azide.
