810320 | Cyanine 5 NHS

Cyanine 5 NHS is an amine-reactive fluorescent probe that combines standard Cyanine 5 with an ester from the N-hydroxysuccinimide (NHS) group. Although it is sometimes called Cy5 dye, as an amine-reactive NHS ester, it is more accurately described as a fluorescent probe for biomolecule conjugation.

This ester derivative probe enables rapid and efficient conjugation to primary amines such as lysine residues on proteins, peptides, and other biomolecules; it's the superior choice for imaging and flow cytometry applications that demand clarity and signal integrity.

Researchers can expect exceptional brightness, impressive photostability, and minimal background interference from Cyanine 5 NHS due to its far-red excitation around 650 nm and strong emission near 670 nm.

Application

Researchers frequently use this probe to create Cy5-conjugated antibodies for immunofluorescence microscopy, Western blot detection, and other protein-labeling needs. Its far-red spectral profile helps reduce cellular autofluorescence, making it highly effective for multiplex imaging workflows. In flow cytometry, it delivers sharp, high-contrast detection within the 650–680 nm channel.

Cyanine 5 NHS also provides great value in research settings that focus on molecular interaction studies, including FRET assays, nucleic acid hybridization, and long-term cell tracking. Its NHS ester chemistry ensures stable, covalent attachment to primary amines, while its compatibility with both aqueous and organic solvents like DMF or DMSO allows for flexible labeling protocols.

Packaging

Our team from Avanti Research™ supplies Cyanine 5 NHS in 5 mg powder packaging, and bulk pricing is available upon request.

Here at Avanti Research™, we specialize in high-quality research reagents designed to meet the rigorous demands of advanced life science applications. With over 50 years of experience and a proven track record across thousands of laboratories, we continue to set the standard for scientific precision with uncompromising adherence to high-quality practices.

Technical & Performance Insights

Cyanine 5 NHS enables straightforward labeling in amine-free buffers such as PBS or MES, with optimal performance observed when conjugating proteins at 10 mg/mL or higher concentrations. Boasting extinction coefficients up to 250,000 M⁻¹cm⁻¹ and quantum yields near 0.2, it delivers performance on par with Cy5 probes trusted by core imaging facilities and flow cytometry labs worldwide.

Users should be aware that cyanine fluorescent probes can undergo blue-conversion artifacts during multicolor imaging; following proper photoprotection protocols helps preserve fluorescence fidelity throughout extended experiments.