ATTO 633 Tetrazine

• Ex/Em: 629/651 nm
• Extinction coefficient: 130,000 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
• Broad Applications: Suited for high-precision techniques such as single-molecule detection and super-resolution microscopy (PALM, dSTORM, STED)

ATTO 633 is a bright-red fluorescent dye, characterized by its strong absorption, high fluorescence quantum yield, and exceptional photo and thermal stability. It exhibits moderate hydrophilicity and is optimally excited within the 610-645 nm wavelength range, compatible with both the 633 nm line of the He-Ne laser and the 635 nm line of the diode laser. 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 633 becomes cationic, carrying a net positive charge of +1. These properties make ATTO 633 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 633 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.