Thermo Scientific DyLight 650-4xPEG Amine-Reactive Dye is a derivative of our high-performance DyLight 650 Dye that can be used to fluorescently label antibodies and other proteins for far-red detection.

The DyLight 650-4xPEG dye contains 4 polyethylene glycol (PEG) chains that are non-cytotoxic, enhance fluorescence, and reduce nonspecific binding of conjugates made with them. Conjugates made with DyLight 650-4xPEG Dye can be used as molecular probes for cellular imaging and other fluorescence detection methods. The far-red to NIR fluorescence properties of DyLight 650-4xPEG Dye make it especially useful in a variety of biological, chemical, and pharmaceutical applications, including in vivo imaging. The PEG chains also improve solubility of the dyes and labeled molecules in aqueous solution, aid in cell permeability, and improve tissue retention.

Features of DyLight 650-4xPEG NHS Ester:

• High fluorescence intensity—significantly brighter fluorescence than Alexa Fluor™ 647
• PEGylated—improves solubility in aqueous solution and aids in cell permeability

Applications:
• Fluorescence microscopy
• In vivo or ex vivo imaging
• Cell-based assays
• Flow cytometry/fluorescence-activated cell sorting (FACS)

DyLight 650-4xPEG Amine-Reactive Dye is activated with an N-hydroxysuccinimide (NHS) ester moiety to react with exposed N-terminal α-amino groups or the ε-amino groups of lysine residues to form stable amide bonds. Learn more about NHS ester chemistry.

Typical labeling reactions require the dye to first be dissolved in anhydrous dimethyl formamide (DMF) or another suitable organic solvent before adding a specific molar amount of dye to an amine-free buffer containing the protein to be labeled. However, the high solubility of DyLight Fluors permits protein solutions to be added directly to the labeling reagent.