XFD514 Tetrazine

XFD514, manufactured by AAT Bioquest, is a bright green-fluorescent dye that is structurally identical to Alexa Fluor™ 514 (ThermoFisher). With optimal excitation between 480-535 nm, it is ideally compatible with the 488 nm line of the Argon-Ion laser and the 532 nm line of the frequency-doubled Nd:YAG laser. XFD514 demonstrates excellent water solubility and remains stable over a wide pH range (pH 4–10), providing consistent and robust fluorescence signals. These properties make it highly suitable for advanced imaging techniques such as fluorescence microscopy and flow cytometry. XFD514 is a suitable replacement for rhodamine 6G.

XFD514 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.