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Cy3 NHS ester (non-sulfonated)

Catalog No.
Labeling of amino-groups in biomolecules.
Grouped product items
SizePriceStock Qty
10mM (in 1mL DMSO)
In stock
In stock
In stock

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Cyanine, a kind of synthetic dye belonging to the polymethine group, is still used in industry to increase the sensitivity range of photographic emulsions (such as increasing the wavelength range and making the film panchromatic), and in biotechnology more recently. As fluorescent dyes, cyanines have been particularly used in biomedical imaging. Depending on their structure, cyanines can cover the spectrum from UV to IR.

Cy3 NHS ester, a reactive dye for labeling of amino-groups in biomolecules, is a Cy3® NHS ester analog. This reagent is commonly used for the labeling of soluble proteins, peptides, and oligonucleotides or DNA. Cy3 NHS ester requires the use of organic co-solvent (such as DMF, or DMSO) for the labeling, however, considering the usage of water-soluble sulfo-Cy3 NHS ester for delicate proteins, such co-solvent is not necessary. Cy3 fluoresce is in the orange region (~550 nm excitation, ~570 nm emission), while Cy5 is fluorescent in the red (~650/670 nm) but absorbs in the orange (~649 nm). Cy3 can be monitored by fluorometers, imagers, and microscopes with standard Tetramethylrhodamine (TRITC) filters. Due to its inherently high extinction coefficient, Cy3 is even detected by naked eye on gels and in solution easily.


Product Citation

Chemical Properties

Physical AppearanceA solid
Storage24 months after receival at -20°C in the dark. Transportation: at room temperature for up to 3 weeks. Avoid prolonged exposure to light. Desiccate.
Solubility≥59mg/mL in DMSO, ≥25.3 mg/mL in EtOH with ultrasonic,insoluble in H2O
Chemical Name(2,5-dioxopyrrolidin-1-yl) 6-[(2E)-3,3-dimethyl-2-[(E)-3-(1,3,3-trimethylindol-1-ium-2-yl)prop-2-enylidene]indol-1-yl]hexanoate
SDFDownload SDF
Shipping ConditionEvaluation sample solution : ship with blue ice.All other available size: ship with RT , or blue ice upon request
General tipsFor obtaining a higher solubility , please warm the tube at 37 ℃ and shake it in the ultrasonic bath for a while.Stock solution can be stored below -20℃ for several months.

Spectral properties

Excitation max (nm) 555 Emission max (nm) 570
Extinction Coefficient (M-1cm-1) 150000 Quantum Yield 0.31
CF260 0.04 CF280 0.09

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