ATTO 620 Tetrazine

• Ex/Em: 619/641 nm
• Extinction coefficient: 120,000 cm^-1M^-1
• Reactive group: Tetrazine
• Rapid Conjugation: Ideal for labeling TCO-modified biomolecules under copper-free conditions, providing fast reaction kinetics
• High Quantum Yield & Stability: Delivers bright, stable fluorescence under prolonged light exposure, temperature changes, and across pH 2–11
• Temperature-Dependent Fluorescence: Enables precise thermal mapping in live cells, protein studies, and reaction monitoring

ATTO 620 is a bright-red fluorescent dye, characterized by its strong absorption, exceptional photo and thermal stability, and temperature-dependent fluorescence. It demonstrates moderate hydrophilicity and optimal excitation within the 600-630 nm wavelength range. The dye maintains stable fluorescence over a wide pH range (2-11), allowing for its use in diverse experimental conditions. Upon conjugation to a substrate, ATTO 620 becomes cationic, carrying a net positive charge of +1. These properties make ATTO 620 particularly suitable for high-precision applications, including single-molecule detection and super-resolution microscopy techniques such as PALM, dSTORM, and STED. Additionally, it is compatible with flow cytometry (FACS), fluorescence in situ hybridization (FISH), and various other biological assays.

ATTO 620 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.