ATTO 425 Tetrazine

• Ex/Em: 438/484 nm
• Extinction coefficient: 45,000 cm^-1M^-1
• Reactive group: Tetrazine
• Click Chemistry Conjugation: Provides rapid and copper-free labeling of TCO-modified biomolecules
• Superior Brightness & Stability: Delivers robust, steady fluorescence for sensitive applications
• Enhanced Signal Separation: Minimal excitation and emission overlap reduces background interference

ATTO 425 is a coumarin-based fluorescent dye characterized by its high fluorescence quantum yield, large Stokes shift, excellent photostability, and low molecular weight. The dye exhibits moderate hydrophilicity and has an optimal excitation range of 405-455 nm. ATTO 425 is particularly suited for applications in single-molecule detection and high-resolution microscopy techniques, including PALM, dSTORM, and STED microscopy. It is also compatible with flow cytometry (FACS), fluorescence in situ hybridization (FISH), and a range of other biological assays.

ATTO 425 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.