SiR-tetrazine (CY-SC008)

SiR-tetrazine is the 4-(1,2,4,5-tetrazin-3-yl)benzylamino derivative of the fluorophore silicon rhodamine (SiR)1) . Sirtetrazine is cell permeable and reacts readily with dienophiles such as trans cyclooctene (TCO), bicyclo[6.1.0]non-4-yn (BCN) and norbornene (Nor) derivatives. Small molecules, peptides, oligonucleotides or proteins bearing the appropriate dienophile can be conjugated to SiR-tetrazine even on live cells. The key features of SiR-tetrazine are i) far-red absorption and emission wavelengths, ii) high extinction coefficient, iii) high photostability, iv) fluorogenic character, v) cell permeability. and vi) compatibility with superresolution microscopy (STED & SIM and STORM)2). The combination of those properties put SiR-tetrazine at the leading edge of excellence.