ATTO 647N DBCO is manufactured by AAT Bioquest for research and development use. ATTO 647N is a rhodamine-based fluorescent dye optimized for use in the red spectral region, with similar spectral characteristics as Cy5. It is characterized by high molar absorptivity, a strong fluorescence quantum yield, and excellent thermal and photostability. The dye is moderately hydrophilic and exhibits optimal excitation within the 625–660 nm range, making it compatible with the 647 nm line of Krypton-Ion lasers and the 650 nm line of diode lasers. ATTO 647N maintains stable fluorescence across a broad pH range (pH 2–11), supporting its application under diverse experimental conditions. Upon conjugation to a substrate, the dye becomes cationic, carrying a net positive charge of +1. Unlike cyanine dyes, ATTO 647N demonstrates enhanced resistance to atmospheric ozone degradation, which increases its reliability in microarray applications. ATTO 647N is particularly effective for high-precision applications such as single-molecule detection, super-resolution microscopy techniques (e.g., SIM and STED), flow cytometry (FACS), fluorescence in situ hybridization (FISH), and various other biological assays.

The DBCO derivative of ATTO 647N 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 647N DBCO serves as an effective alternative to copper-dependent fluorescent alkynes.