XFD430 Tetrazine

• Ex/Em: 432/540 nm
• Extinction coefficient: 15,000 cm^-1M^-1
• Reactive Group: Tetrazine
• Click Chemistry Conjugation: Provides rapid, copper-free labeling of TCO-modified biomolecules
• pH-Insensitive & High Hydrophilicity: Maintains stable fluorescence across pH 4–10 and minimizes aggregation
• Large Stokes Shift: Provides clear signal separation and minimizes spectral overlap, enhancing imaging accuracy in sensitive applications

XFD430, manufactured by AAT Bioquest, is a green-fluorescent dye that is structurally identical to Alexa Fluor™ 430 (ThermoFisher). With excitation and emission maxima at 432 nm and 540 nm, respectively, it is optimally excited by a 405 nm violet laser. Its large Stokes shift reduces spectral overlap with blue-emitting fluorophores, providing a superior signal-to-noise ratio in multiplexed fluorescence assays. XFD430 also exhibits good water solubility and remains pH-insensitive across a wide range (pH 4–10), making it well-suited for generating stable, reproducible fluorescence signals in both microscopy and flow cytometry applications.

XFD430 tetrazine is particularly useful for labeling TCO-modified biomolecules under copper-free conditions. It reacts with TCO-functionalized molecules, forming a stable conjugate via a dihydropyrazine moiety. This click reaction is favored over others due to its extremely fast kinetics and higher yields under mild reaction conditions, making it a popular choice for researchers.