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) that 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 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.