Sulfo-Cy5-TCO | CAS 2129525-69-3

Sulfo-Cy5-TCO is a water-soluble, Cy5-based click chemistry reagent that combines a bright far-red fluorophore with a trans-cyclooctene (TCO) handle for rapid bioorthogonal labeling. In fluorescence workflows, it enables direct visualization of biomolecules, surfaces, and materials through strain-promoted trans-cyclooctene-tetrazine ligation, with the sulfonate functionality supporting aqueous conjugation and imaging compatibility.

1. Biomolecule Labeling

Sulfo-Cy5-TCO is used by chemical biology and protein chemistry teams to fluorescently tag biomolecules via TCO-mediated click labeling, supporting downstream fluorescence imaging and quantification. Researchers commonly incorporate it into labeling strategies for antibodies, peptides, and other targeting ligands that are subsequently conjugated to tetrazine-bearing partners, enabling far-red readouts that are well matched to standard fluorescence imaging and plate-based detection workflows.

2. Cell-Surface Imaging

Sulfo-Cy5-TCO is employed in cell biology laboratories to label extracellular or cell-surface accessible components when paired with tetrazine-functional targeting reagents. The far-red Cy5 emission helps reduce interference from cellular autofluorescence in many microscopy setups, while the sulfonate-driven water solubility supports practical staining and wash steps during microscopy experiments, including localization studies of labeled biomolecular assemblies on living or fixed cell preparations.

3. Fluorescent Probe Construction

Sulfo-Cy5-TCO is frequently used in fluorescent probe development to build modular imaging reagents that can be rapidly assembled from a Cy5 fluorophore-bearing TCO component and a tetrazine-functional recognition or delivery element. This approach is particularly valuable for researchers designing conjugates for molecular imaging reagent libraries, where the Cy5 reporter provides consistent far-red tracking while the click handles support flexible interchange of targeting scaffolds.

4. Biomaterial Surface Functionalization

Sulfo-Cy5-TCO supports biomaterials research and surface engineering by enabling far-red fluorescent labeling of tetrazine-functional coatings, hydrogels, and engineered surfaces. Materials scientists use the reagent to visualize and verify surface modification patterns, monitor conjugation coverage in aqueous environments, and create fluorescently traceable materials for microscopy-based characterization of functionalized biomaterials and interfaces.