ATTO 495 DBCO

• Ex/Em: 497/525 nm
• Extinction coefficient: 80,000 cm^-1M^-1
• Reactive group: DBCO
• Copper-Free Bioorthogonal Labeling: Enables rapid and efficient azide conjugation via copper-free SPAAC
• Superior Brightness & Stability: Delivers intense fluorescence with high photostability and thermal stability
• Long-Lived Phosphorescence: Enables sustained emission in solid matrices or at low temperatures, ideal for time-resolved spectroscopy
• Hydrophilic PEG3 Spacer: Improves solubility and minimizes steric hindrance for enhanced biocompatibility

ATTO 495 is a green fluorescent dye derived from acridine orange, known for its strong absorption, high fluorescence quantum yield, excellent photostability, and superior thermal stability. It exhibits moderate hydrophilicity and is highly soluble in polar solvents such as DMF and DMSO, with an optimal excitation range of 465-510 nm. Notably, ATTO 495 exhibits intense and long-lived phosphorescence in solid matrices or at low temperatures. This dye is well-suited for advanced applications in single-molecule detection and high-resolution microscopy techniques, such as PALM, dSTORM, and STED microscopy. It is also compatible with flow cytometry (FACS), fluorescence in situ hybridization (FISH), and a wide range of other biological assays.

The DBCO derivative of ATTO 495 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 495 DBCO serves as an effective alternative to copper-dependent fluorescent alkynes.