Sulfo-cyanine3 azide TEA is a water-soluble cyanine dye and fluorescent probe (Ex/Em=548/563 nm). This compound can be involved in the synthesis of fused tricyclic heterocycles and the preparation of immune stimulants. It contains an Azide group, allowing it to undergo copper-catalyzed azide-alkyne cycloaddition (CuAAc) with molecules containing an Alkyne group. Additionally, it can participate in strain-promoted azide-alkyne cycloaddition (SPAAC) with molecules that have DBCO or BCN groups.