sulfo-Cyanine7.5 is a heptamethyne cyanine dye for the near-infrared region of the spectrum, which is very hydrophilic and water-soluble. The fluorophore resembles ICG (Indocyanine Green), has a long history of in vivo use, and is even approved for human angiography. However, compared to ICG, sulfo-Cyanine7.5 has a significantly improved fluorescence quantum yield due to the rugged polymethine chain reinforced with a trimethylene bridge.
sulfo-Cyanine7.5 is available as a number of reactive derivatives. This azide can be used for the easy labeling of various biomolecules by copper-catalyzed or copper-free click chemistry.