Cyanine3.5 azide chloride is analogous to Cyanine3.5 azide and serves as an efficient green fluorescent dye. This compound utilizes click chemistry for ethyl labeling (λex=591 nm, λem=604 nm). Cyanine3.5 azide (chloride) acts as a click chemistry reagent, featuring an azide group that can engage in copper-catalyzed azide-alkyne cycloaddition (CuAAC) with molecules containing alkyne groups. Additionally, it can undergo strain-promoted azide-alkyne cycloaddition (SPAAC) with molecules that have DBCO or BCN groups.