Cy3 alkyne is a water-insoluble dye ready for the use in Click Chemistry reaction. With this bright and photostable reagent, molecules bearing azide group can be attached by it. The reagent can be efficiently attached to water-soluble molecules such as proteins when used with organic co-solvent (DMSO or DMF). For biomolecule labeling, 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. Most derivatives of non-sulfonated cyanines have low aqueous solubility except for hydrochlorides of hydrazides and amines.
