ATTO 550 azide is the azide derivative of ATTO 550, with maximum excitation/emission wavelengths of 554/576 nm. As a click chemistry reagent, ATTO 550 azide contains an azide group that can participate in copper-catalyzed azide-alkyne cycloaddition (CuAAC) with alkyne-containing molecules. It also undergoes strain-promoted azide-alkyne cycloaddition (SPAAC) with molecules that have DBCO or BCN groups.