CY5-YNE (Sulfo-Cyanine5-alkyne) triethylamine is a reactive dye utilized for labeling amino groups on peptides, proteins, and oligonucleotides (Ex: 650 nM; Em: 680 nm). As a click chemistry reagent, CY5-YNE triethylamine includes an alkyne group that engages in copper-catalyzed azide-alkyne cycloaddition reactions (CuAAc) with azide-containing molecules.