Sulfo-Cyanine5 azido (ethyl) | CAS 1048022-24-7

Sulfo-Cyanine5 azido (ethyl) is a water-soluble, sulfonated cyanine dye bearing an azide functional group for click chemistry bioconjugation. In fluorescent labeling workflows, the Cy5 chromophore provides red emission for microscopy and fluorescence-based assays, while the azide handle enables efficient attachment to complementary alkyne partners on biomolecules, polymers, and surfaces. This reagent is commonly used to construct Cy5-labeled conjugates where aqueous compatibility and modular dye installation are required.

1. Biomolecule Labeling

Sulfo-Cyanine5 azido (ethyl) is used to generate Cy5 fluorescent conjugates for proteins, peptides, and other biomolecules in chemical biology and assay development. Researchers typically install the dye onto an alkyne-functionalized biomolecule (or onto a capture reagent) to produce labeling reagents for fluorescence imaging, binding studies, and quantitative fluorescence readouts. The sulfonated dye design supports aqueous workflows where conjugates must remain dispersible during staining, washing, and imaging steps.

2. Fluorescent Probe Construction

Sulfo-Cyanine5 azido (ethyl) serves as a modular fluorophore building block for fluorescent probe development and molecular imaging reagent assembly. Teams designing targeted or activity-responsive probes often use the azide functionality to incorporate a Cy5 reporter into larger probe architectures, including multicomponent constructs and labeled affinity probes for microscopy and plate-based fluorescence assays. The red-emitting Cy5 reporter is frequently selected when spectral separation from green channels is needed for multiplexed imaging or multi-color assay panels.

3. Surface And Polymer Functionalization

Sulfo-Cyanine5 azido (ethyl) is applied to functionalize biomaterials, nanoparticles, and polymeric platforms that have been prepared with complementary alkyne groups. In materials and biosensor research, the dye installation enables visualization of surface-bound components and supports fluorescence tracking of coatings, immobilized ligands, and engineered interfaces. The water-soluble sulfonate substituents help maintain dye performance in aqueous buffers used for surface coupling, washing, and downstream characterization.

4. Fluorescence Microscopy Staining

Sulfo-Cyanine5 azido (ethyl) is used to prepare Cy5-labeled staining reagents for fluorescence microscopy experiments requiring red channel imaging. Investigators incorporate the azide dye into labeling constructs that target specific biomolecular features or marker reagents, then use the resulting conjugates to visualize localization patterns in fixed-cell or cleared-sample workflows. The dye's Cy5 emission supports compatibility with standard fluorescence microscope filter sets designed for far-red/red detection, enabling clear channel separation in multi-label studies.