ATTO 633 DBCO

• Ex/Em: 629/651 nm
• Extinction coefficient: 130,000 cm^-1M^-1
• Reactive group: DBCO
• Copper-Free Bioorthogonal Labeling: Enables efficient azide conjugation via SPAAC without copper, ideal for sensitive systems
• 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.

The DBCO derivative of ATTO 633 is a highly reactive cycloalkyne optimized for copper-free click chemistry (SPAAC, strain-promoted azide-alkyne cycloaddition). This derivative exhibits a significantly higher reaction rate with azides compared to other cyclooctynes and copper-catalyzed click reactions (CuAAC). Uniquely, DBCO does not react with tetrazines, allowing for its use in bioorthogonal reactions alongside trans-cyclooctenes and tetrazines. For applications where the presence of copper is problematic, ATTO 633 DBCO serves as an effective alternative to copper-dependent fluorescent alkynes.