Thermo Scientific DyLight 755 Amine-Reactive Dye is an NHS ester-activated derivative of high-performance DyLight 755 used to fluorescently label antibodies and other proteins that are then used as molecular probes for cellular imaging and other fluorescence detection methods.

DyLight 755 is a near-IR fluor that is invisible to the naked eye but increases the staining options when using infrared imaging systems. DyLight 755 has spectral properties that are very similar to other near-IR dyes, including Alexa Fluor™ 750. The high water solubility of DyLight Fluors means that a high dye-to-protein ratio can be attained without causing precipitation of the conjugates. DyLight 755 Amine-Reactive Dye is also available as part of two antibody labeling kit sizes.

Features of DyLight 755 NHS Ester:

• High performance—DyLight 755 replaces Alexa Fluor 755 for near-infrared staining
• Specific—NHS ester-activated dye labels proteins and other molecules at primary amines (-NH2)
• Optimized procedure—following the standard protocol results in antibodies with excellent dye:protein ratios and recovery rates for optimum activity and fluorescence labeling

Applications:
• Primary antibody labeling for immunofluorescence microscopy, immunohistochemistry (IHC), Western blotting or ELISA assay
• Target protein labeling for in vitro and in vivo fluorescent detection strategies

DyLight 755 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 specific amounts of the labeling reagent. This feature allows DyLight 755 Amine-Reactive Dye to be provided in multiple formats with flexible protocols to achieve efficient degrees of labeling.

We also offer Standard and Microscale DyLight 755 Antibody Labeling Kits for fast and efficient fluorescent labeling of antibodies for use in fluorescence methods.The standard size kit contains all necessary components to perform three separate labeling reactions using 1 mg of IgG or similar quantities of other proteins. The microscale kit contains all of the necessary components to perform five separate labeling reactions using 100 μg of IgG. Both kit sizes include the Amine-Reactive DyLight 755 NHS-ester in convenient single-use vials as well as purification resin and spin columns for the preparation of ready-to-use conjugate.

Related Products
DyLight™ 755 Antibody Labeling Kit
DyLight™ 755 Microscale Antibody Labeling Kit