ATTO 680 PEG3 azide

• Ex/Em: 679/696 nm
• Extinction Coefficient: 125,000 M⁻¹cm⁻¹
• Reactive Group: Azide
• Click Chemistry Conjugation: Efficiently labels terminal alkynes via CuAAC and copper-free SPAAC, perfect for peptides, antibodies, and biomolecules
• High Quantum Yield & Stability: Delivers bright, photostable fluorescence with strong thermal resilience
• Hydrophilic PEG3 Spacer: Enhances solubility and minimizes steric hindrance for enhanced biocompatibility
• Zwitterionic: Minimizes non-specific binding to biological surfaces, reducing background noise in live-cell imaging and super-resolution microscopy

ATTO 680 is a far-red fluorescent dye characterized by its strong absorption, high photo and thermal stability, and good aqueous solubility. It is optimally excited within the 645-695 nm wavelength range, which aligns with the 670 nm line of diode laser and the 676 nm line of Krypton-Ion laser. As a zwitterionic compound, ATTO 680 remains electrically neutral when conjugated to biomolecules or other substrates. Its strong electron-accepting properties result in efficient fluorescence quenching by electron donors such as guanine and tryptophan. These properties make ATTO 680 ideal for precise applications including single-molecule detection and super-resolution microscopy techniques like PALM, dSTORM, and STED. Furthermore, ATTO 680 is compatible with flow cytometry (FACS), fluorescence in situ hybridization (FISH), and a variety of other biological assays, making it a versatile tool in advanced fluorescence-based research.

The azide derivative of ATTO 680 is widely used for labeling terminal alkynes on peptides, antibodies, and other biomolecules via click chemistry. It participates in copper-catalyzed azide-alkyne cycloaddition (CuAAC) with alkyne-containing molecules and strain-promoted alkyne-azide cycloaddition (SPAAC) with DBCO- or BCN-containing molecules.