ICG-TFP ester

Indocyanine green (ICG) is a cyanine dye used in medical diagnostics. It is used for determining cardiac output, hepatic function, and liver blood flow, and for ophthalmic angiography. It has a peak spectral absorption close to 800 nm. These infrared frequencies penetrate retinal layers, allowing ICG angiography to image deeper patterns of circulation than fluorescein angiography. The amino-reactive ICG-Sulfo-OSu (#180) is predominantly used to make various ICG bioconjugates with antibodies and other biological molecules since it has improved water solubility compared to other ICG amine-reactive derivatives. However, the well-known ICG-Sulfo-OSu is extremely unstable. ICG-TFP ester has significantly improved stability and good water solubility. Under the same conditions, it gives higher conjugation yield than ICG-Sulfo-OSu.