DyLight™ 550 NHS Ester

Catalog number: 62262B

Thermo Scientific™  Related applications: Protein Labeling & Crosslinking

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Thermo Scientific DyLight 550 Amine-Reactive Dye is an NHS ester-activated derivative of high-performance DyLight 550 used to fluorescently label antibodies and other proteins that are then used as molecular probes for cellular imaging and other fluorescence detection methods.

DyLight 550 provides vibrant orange-to-red fluorescence with better performance than other rhodamine derivatives, including Alexa Fluor™ 555, TRITC, and Cy3™ dye for fluorescent applications. 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 550 Amine-Reactive Dye is also available as part of two antibody labeling kit sizes.

Features of DyLight 550 NHS Ester:

High performance—DyLight 550 shows brighter fluorescence than Alexa Fluor 555, TRITC, and Cy3 dye
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

• 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 550 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 DyLight 550 Amine-Reactive 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 550 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 550 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 550 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™ 550 Antibody Labeling Kit
DyLight™ 550 Microscale Antibody Labeling Kit
For Research Use Only. Not for use in diagnostic procedures.


Label or Dye: DyLight™ 550
Chemical Reactivity: Amine
Solubility: DMF (Dimethylformamide)
Product Size: Custom
Excitation⁄Emission (nm): 562⁄576

Contents & storage

Store desiccated at -20°C.


Manuals & protocols