Cyanine5 NHS ester – CAS 1263093-76-0


Cyanine5 NHS ester – CAS 1263093-76-0 is provided by Santiago Lab (Prague, Czech Republic)

Purity (LC-MS)

min 95%

Package contents

Cyanine5 NHS ester

This compound is for research use only. We do not sell to patients.
25 mg

In stock

100 mg

In stock

250 mg

In stock


Cyanine5 NHS ester – CAS 1263093-76-0


CAS: 1263093-76-0

IUPAC Name: (2,5-dioxopyrrolidin-1-yl) 6-[(2E)-3,3-dimethyl-2-[(2E,4E)-5-(1,3,3-trimethylindol-1-ium-2-yl)penta-2,4-dienylidene]indol-1-yl]hexanoate;tetrafluoroborate

Other names: Cyanine5 NHS ester, Cy5-NHS ester tetrafluoroborate,

Molecular weight: 667.5 g/mol

Molecular formula: C36H42BF4N3O4

InChI: InChI=1S/C36H42N3O4.BF4/c1-35(2)26-16-11-13-18-28(26)37(5)30(35)20-8-6-9-21-31-36(3,4)27-17-12-14-19-29(27)38(31)25-15-7-10-22-34(42)43-39-32(40)23-24-33(39)41;2-1(3,4)5/h6,8-9,11-14,16-21H,7,10,15,22-25H2,1-5H3;/q+1;-1

Solubility: Poor solubility in water,  good in polar (DMSO, DMF) and chlorinated (DCM, chloroform) organic solvents

Excitation/absorption maximum: 646 nm

Emission maximum: 662 nm

Extinction Coefficient: 250000 M-1cm-1


In recent years, Cyanine5, a robust analog of Cy5®, has gained significant popularity as a label in both life science research and diagnostics. With its emission maximum in the red region, aligning with the peak sensitivity of many CCD detectors, and minimal background in biological objects, Cyanine5 stands out. The intense color of this dye allows for the detection of quantities as small as 1 nmol in gel electrophoresis with the naked eye.

Our Cyanine5 NHS ester, an analog to Cy5® NHS ester, is a reactive dye designed for efficient labeling of amino-groups in peptides, proteins, and oligonucleotides. While requiring a small amount of organic co-solvent (such as DMF or DMSO) in labeling reactions, it offers a cost-efficient solution for labeling soluble proteins, peptides, and oligonucleotides. Additionally, it performs well in organic solvents for small molecule labeling. For applications where the use of DMF or DMSO is undesirable, our water-soluble sulfo-Cyanine 5 NHS ester, with similar fluorescent properties, is recommended.

The versatility of Cyanine5 fluorophore extends to its compatibility with various instrumentation, including fluorescent microscopes, imagers, scanners, and fluorescence readers. Numerous Cyanine5 analogs are available, with Cyanine5 NHS ester seamlessly replacing activated esters of Cy5® and DyLight 649. Explore the possibilities with our Cyanine5 derivatives for enhanced flexibility and performance in your experiments.


  • Shukla S, Wang C, Beiss V, Steinmetz NF. Antibody Response against Cowpea Mosaic Viral Nanoparticles Improves In Situ Vaccine Efficacy in Ovarian Cancer. ACS Nano. 2020;14(3):2994-3003. doi:10.1021/acsnano.9b07865


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