Cyanine5 NHS ester

NHS esters Cyanine5 Protein labeling

Cat. #	Quantity	Price	Lead time
13020	1 mg	$87	in stock
23020	5 mg	$117	in stock
43020	25 mg	$337	in stock
53020	50 mg	$550	in stock
63020	100 mg	$870	in stock
83020	1 g	please inquire	12 days

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During the last years, Cyanine5 (an analog of Cy5^®) has become an incredibly popular label in life science research and diagnostics. The fluorophore has its emission maximum in the red region, where many CCD detectors exhibit maximum sensitivity, and biological objects show low background. The dye color is very intense, therefore quantities as small as 1 nmol can be detected in gel electrophoresis by naked eye.

This Cyanine5 NHS ester (analog to Cy5^® NHS ester) is a reactive dye for the labeling of amino-groups in peptides, proteins, and oligonucleotides. This dye requires a small amount of organic co-solvent (such as DMF or DMSO) to be used in labeling reactions (please see our recommended protocol for more details). This reagent is ideal for very cost-efficient labeling of soluble proteins as well as all kinds of peptides and oligonucleotides. This reagent also works well in organic solvents for small molecule labeling. For more sophisticated targets such as easily degradable proteins, when the use of DMF or DMSO is undesirable, consider using water-soluble sulfo-Cyanine 5 NHS ester which does not require any co-solvent, and features very similar fluorescent properties.

Cyanine5 fluorophore is compatible with various instrumentation including many fluorescent microscopes, imagers, scanners, and fluorescence readers. A number of various Cyanine5 analogs exist - Cyanine5 NHS ester can replace activated esters of Cy5® and DyLight 649.

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Cy5 excitation and emission spectra

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What is the proper color of Cyanine5 succinimidyl ester?

General properties

Appearance:	dark colored solid
Molecular weight:	667.54
CAS number:	1263093-76-0
Molecular formula:	C₃₆H₄₂N₃BF₄O₄
IUPAC name:	3H-Indolium, 2-[5-(1,3-dihydro-1,3,3-trimethyl-2H-indol-2-ylidene)-1,3-pentadien-1-yl]-1-[6-[(2,5-dioxo-1-pyrrolidinyl)oxy]-6-oxohexyl]-3,3-dimethyl-, tetrafluoroborate
Solubility:	very poorly soluble in water (0.19 mM = 127 mg/L), good in polar (DMSO, DMF) and chlorinated (DCM, chloroform) organic solvents
Quality control:	NMR ¹H, HPLC-MS (95%)
Storage conditions:	Storage: 12 months after receival at -20°C in the dark. Transportation: at room temperature for up to 3 weeks. Avoid prolonged exposure to light. Desiccate.
MSDS:	Download
	Product specifications

Spectral properties

Excitation/absorption maximum, nm:	646
ε, L⋅mol⁻¹⋅cm⁻¹:	250000
Emission maximum, nm:	662
Fluorescence quantum yield:	0.2
CF₂₆₀:	0.03
CF₂₈₀:	0.04

Product citations

Oh, H. J.; Lee, Y.; Hwang, H.; Hong, K.; Choi, H.; Kang, J. Y.; Jung, Y. Size-Controlled Assembly of Phase Separated Protein Condensates with Interfacial Protein Cages. Nat Commun, 2025, 16(1), 1009. doi: 10.1038/s41467-025-56391-y
Horvat, N. K.; Chocarro, S.; Marques, O.; Bauer, T. A.; Qiu, R.; Diaz-Jimenez, A.; Helm, B.; Chen, Y.; Sawall, S.; Sparla, R.; Su, L.; Klingmüller, U.; Barz, M.; Hentze, M. W.; Sotillo, R.; Muckenthaler, M. U. Superparamagnetic Iron Oxide Nanoparticles Reprogram the Tumor Microenvironment and Reduce Lung Cancer Regrowth after Crizotinib Treatment. ACS Nano, 2024, 18(17), 11025–11041. doi: 10.1021/acsnano.3c08335
Solé‐Porta, A.; Areny‐Balagueró, A.; Camprubí‐Rimblas, M.; Fernández Fernández, E.; O’Sullivan, A.; Giannoccari, R.; MacLoughlin, R.; Closa, D.; Artigas, A.; Roig, A. Efficient Nebulization and Pulmonary Biodistribution of Polymeric Nanocarriers in an Acute Lung Injury Preclinical Model. Small Science, 2024, 4(9), 2400066. doi: 10.1002/smsc.202400066
Xing, W.; Li, D.; Wang, W.; Liu, J.-J.G.; Chen, C. Conformational dynamics of CasX (Cas12e) in mediating DNA cleavage revealed by single-molecule FRET. Nucleic Acids Research, 2024. doi: 10.1093/nar/gkae604