XFD635 Maleimide

• Ex/Em: 633/647 nm
• Extinction Coefficient: 140,000 cm^-1M^-1
• Reactive Group: Maleimide
• Versatile Conjugation: Efficiently labels thiol groups on proteins, antibodies, and oligonucleotides with stable thioether bonds
• Advanced Dye Properties: Excellent water solubility and structural match to Alexa Fluor™ 635
• Robust Signal Performance: Maintains high intensity and pH independence (pH 4-11) with exceptional photostability

XFD635, manufactured by AAT Bioquest, is a bright far red-fluorescent dye structurally identical to Alexa Fluor™ 635 (ThermoFisher). It is characterized by its intense brightness, high fluorescence quantum yield and photostability. The dye demonstrates excellent solubility in aqueous solutions and retains pH-independent fluorescence over a broad range (pH 4–11), ensuring consistent performance across diverse experimental conditions. Optimally excited by the 633 nm emission line of He-Ne lasers or the 635 nm diode laser, XFD635 is particularly well-suited for flow cytometry. Its robust and uniform labeling properties yield high signal intensity and reproducibility, making it an ideal choice for advanced fluorescence imaging, flow cytometry, and various fluorescence-based analytical techniques.

The maleimide derivative of XFD635 is widely used for labeling biomolecules with free thiol (SH) groups, including antibodies, proteins, thiol-modified oligonucleotides, and low molecular weight ligands. Maleimides react readily with sulfhydryl groups, forming stable thio-ether bonds between the dye and the biomolecule, facilitating robust and reliable labeling for diverse experimental applications.