XFD647 Tetrazine

• Ex/Em: 650/671 nm
• Extinction coefficient: 270,000 cm^-1M^-1
• Reactive Group: Tetrazine
• Click Chemistry Conjugation: Provides rapid and copper-free labeling of TCO-modified biomolecules
• Bright & Stable: Delivers intense fluorescence with resilience to photobleaching and pH variations from 4 to 10
• Hydrophilic: Minimizes aggregation, enhancing signal clarity for advanced imaging and live-cell studies

XFD647, manufactured by AAT Bioquest, is a bright far-red flurosecent dye structurally identical to Alexa Fluor™ 647 (ThermoFisher). It is efficiently excited by the 594 nm or 633 nm laser lines and is compatible with RFP filters like Cy5, making it well-suited for applications such as fluorescence microscopy and flow cytometry. XFD647 exhibits excellent aqueous solubility and pH stability across a wide range (pH 4–10), ensuring robust signal reproducibility under diverse experimental conditions. The dye enables high-degree conjugation to biomolecules with minimal self-quenching, resulting in enhanced fluorescence intensity and signal stability. Additionally, its high fluorescence quantum yield and superior photostability facilitate the sensitive detection of low-abundance targets, enhancing precision and sensitivity in quantitative fluorescence-based assays.

XFD647 tetrazine is particularly useful for labeling TCO-modified biomolecules under copper-free conditions. It reacts with TCO-functionalized molecules, forming a stable conjugate via a dihydropyrazine moiety. This click reaction is favored over others due to its extremely fast kinetics and higher yields under mild reaction conditions, making it a popular choice for researchers.