Description
sulfo-Cyanine5.5 is a water-soluble, hydrophilic fluorophore with emission in the far-red area of the spectrum, an analog of Cy5.5®. Like other cyanine dyes, sulfo-Cyanine5.5 has an outstanding molar extinction coefficient, giving rise to its bright fluorescence. The molecule contains four sulfo groups that provide hydrophilicity and negative charge to the fluorophore — this minimizes non-specific binding.
The azide group of Sulfo-Cyanine5.5 azide can be conjugated with terminal alkynes in the presence of copper(I) catalyst or with cycloalkynes in copper-free strain-promoted reaction.
The reagent possesses high hydrophilicity and is recommended for labeling biomolecules in an aqueous environment.
Chemical Properties
Appearance: Dark blue solid
ex/em: 678/706 nm (PBS buffer)
Extinction coefficient (ε): 211000 Lmol1cm1
Quantum yield (Φ): 0.21
Uses
Sulfo-Cyanine5.5 azide tripotassium, a near-infrared (NIR) fluorescent dye, is an azide-functionalized Sulfo-Cyanine5.5 (Ex=678 nm, Em=694 nm). Sulfo-Cyanine5.5 azide tripotassium can react with alkynes for Click Chemistry labeling[1]. It contains an azide group and can undergo copper-catalyzed azide-alkyne cycloaddition (CuAAc) with molecules containing alkyne groups. It can also undergo ring strain-promoted alkyne-azide cycloaddition (SPAAC) with molecules containing DBCO or BCN groups.
References
[1] Katrin Spinnler, et al. An Alkyne-functionalized Arginine for Solid-Phase Synthesis Enabling "Bioorthogonal" Peptide Conjugation. ACS Med Chem Lett. 2019 Sep 30;11(3):334-339. DOI:
10.1021/acsmedchemlett.9b00388
Fluoresene quantum yield
0.21
Extinction Coefficient
211000
