Name: Cy5 BCN
Brand: AAT Bioquest
SKU: 70542
Price: 112 USD
Availability: InStock

Cy5 BCN

Cy5 BCN is a bright far-red fluorescent dye used for site-specific labeling of peptides, oligonucleotides, and other biomolecules via copper-free click chemistry.

Bioorthogonality: The reaction is selective for azido or tetrazine.
High reaction rate: BCN reacts faster than most other click reactions.
Catalyst-free: The reaction does not require a toxic metal catalyst like copper.
High biocompatibility: The reaction occurs under physiological pH and room temperature.
Versatility: It can be used for site-specific modification of a wide range of macromolecules.

Protocol

SDS

COA

Catalog	Size	Price	Quantity
70542	1 mg	Price

Overview

Cy5 BCN is a clickable derivative of Cy5, a popular far-red fluorescent dye used for labeling peptides, oligonucleotides, and other biomolecules. Cy5 is characterized by a strong fluorescence intensity, high photostability, and compatibility as an acceptor fluorophore in FRET assays with Cy3 as the donor. To improve conjugation performance, Cy5-BCN incorporates a PEG spacer, which reduces steric hindrance and minimizes potential interference with target binding sites. This design maximizes conjugation efficiency while preserving the biological activity of the resulting conjugate. The bicyclononyne (BCN) moiety enables strain-promoted azide–alkyne cycloaddition (SPAAC) with azido groups, forming stable triazole linkages under catalyst-free conditions. In addition, unlike dibenzocyclooctyne (DBCO), BCN also reacts efficiently with tetrazines through an inverse electron-demand Diels–Alder (IEDDA) reaction. This reaction is rapid, selective, and bioorthogonal, allowing labeling of biomolecules under physiological conditions without the need for metal catalysts or disruption of native biological processes.

References

View all 50 references: Citation Explorer

Unsaturated Phosphine Oxides for Modular Antibody Rebridging and Single Reagent Peptide-Cyclization-Bioconjugation.

Authors:

Stieger, Christian E and McMillan, Alastair J and de Geus, Mark A R and Arafiles, Jan Vincent V and Franz, Luise and Hackenberger, Christian P R

Journal:

Angewandte Chemie (International ed. in English) (2025): e202508656

Cyclooctyne-Functionalized N-Heterocyclic Carbenes for Click Coupling of Sensing Oligonucleotides to Gold Surfaces.

Authors:

Nalaoh, Phattananawee and Clark, Vincent and Arroyo-Currás, Netzahualcóyotl and Jenkins, David M

Journal:

ACS sensors (2025): 6039-6047

Effect of Click Chemistry Linkages on the Biological Behavior of Albumin-Binding 177Lu-DOTAGA-pIBA-LLP2A Analogues Targeting Melanoma.

Authors:

Li, Longbo and Wirrick, Aidan and Pun, Michael D and Lovingier, Christine L and Gallazzi, Fabio and Fong, Cyril O Y and Watkinson, Lisa and Carmack, Terry L and Rodgers, Mikayla and Tucker, Katherine and Ho, Khanh-Van and Anderson, Carolyn J

Journal:

Bioconjugate chemistry (2025): 2002-2012

Cyclooctyne End-Functionalized Poly(morpholine-2,5-dione)s.

Authors:

Schreiber, Johanna and Göppert, Natalie E and Stafast, Leanne M and Weber, Christine and Schubert, Ulrich S

Journal:

Macromolecular rapid communications (2025): e2400705

Bioorthogonal SERS-bioluminescence dual-modal imaging for real-time tracking of triple-negative breast cancer metastasis.

Authors:

Zhang, Wei and Wang, Sisi and Xing, Yanlong and Luo, Xianzhu and Wang, Rui and Yu, Fabiao

Journal:

Acta biomaterialia (2025): 431-443

Physical properties

Solvent

DMSO

Spectral properties

Correction factor (260 nm)	0.02
Correction factor (280 nm)	0.03
Correction factor (482 nm)	0.009
Correction factor (565 nm)	0.09
Extinction coefficient (cm ^-1 M ^-1)	250000 ¹
Excitation (nm)	651
Emission (nm)	670
Quantum yield	0.27 ¹ , 0.4 ²

Storage, safety and handling

H-phrase	H303, H313, H333
Hazard symbol	XN
Intended use	Research Use Only (RUO)
R-phrase	R20, R21, R22
Storage	Freeze (< -15 °C); Minimize light exposure

Documents

Protocol
Safety Data Sheet
Certificate of Analysis

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Fax
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Page updated on December 8, 2025