AF647 Azide is a fluorescently labeled azide that reacts with alkynyl derivatives of biomolecules (terminal alkynes and cyclooctynes) via click reactions to form stable adducts. AF647 is a bright, photostable, and hydrophilic fluorophore emitting in the far-red channel (absorption max. is 650 nm, emission max. is 671 nm). AF647 azide is useful for cell labeling, fluorescence microscopy, and flow cytometry.