XFD790 PEG4 DBCO

• Ex/Em: 782/805 nm
• Extinction coefficient: 260,000 cm^-1M^-1
• Reactive Group: DBCO
• Copper-Free Bioorthogonal Labeling: Enables rapid and efficient azide conjugation via copper-free SPAAC
• Water Soluble: Minimizes aggregation, enhancing signal clarity for advanced imaging and live-cell studies
• Reduced Autofluorescence: Long-wavelength emission minimizes background interference, enhancing signal-to-noise ratios in complex biological matrices.
• Panel Optimization: Well-separated from far-red fluorophores such as iFluor® 647 and allophycocyanin (APC), facilitating precise multicolor fluorescence detection.

XFD790, manufactured by AAT Bioquest, is a highly efficient near-infrared fluorescent dye that is structurally identical to Alexa Fluor™ 790 (ThermoFisher). Spectrally analogous to indocyanine green (ICG) and IRDye™ 800, XFD790 demonstrates exceptional aqueous solubility and sustained fluorescence stability over a broad pH range (pH 4–10), ensuring consistent and reproducible performance across diverse experimental conditions. Its long-wavelength emission effectively mitigates background autofluorescence, thereby enhancing signal-to-noise ratios in complex biological matrices, including tissue samples. As the longest-wavelength fluorophore in the XFD series, XFD790 offers superior spectral separation from widely used far-red fluorophores such as iFluor® 647, XFD647, and allophycocyanin (APC), facilitating precise multicolor fluorescence analyses. Furthermore, its optical properties make it an excellent candidate for small animal in vivo imaging (SAIVI) and two-color western blot applications using the LI-COR™ Odyssey™ infrared imaging system.

The DBCO derivative of XFD790 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, XFD790 DBCO serves as an effective alternative to copper-dependent fluorescent alkynes.