Sulfo-Cy3-Methyltetrazine | CAS 1801924-47-9

Sulfo-Cy3-Methyltetrazine is a sulfonated, Cy3-based fluorescent labeling reagent incorporating a methyltetrazine functional group for rapid tetrazine/trans-cyclooctene click chemistry. Its bright red emission and water-compatible sulfonated scaffold make it well suited for constructing fluorescent bioconjugates, imaging probes, and labeling reagents where fast, bioorthogonal tagging is required. In practice, it is used to visualize biomolecules and biomaterial surfaces that have been pre-functionalized with a complementary trans-cyclooctene handle, enabling efficient post-labeling with a Cy3 fluorophore.

1. Biomolecule Labeling

Sulfo-Cy3-Methyltetrazine is widely used by chemical biology and glycobiology groups to fluorescently tag proteins, peptides, and other biomolecules that carry a trans-cyclooctene (TCO) group. Researchers typically apply it in workflows where a TCO-functionalized targeting ligand (for example, an affinity reagent or biomolecule-binding component) is first prepared, followed by rapid Cy3 labeling for downstream fluorescence imaging and quantitative readouts. The sulfonated Cy3 scaffold supports aqueous labeling conditions, making it practical for conjugate preparation for microscopy-based localization studies and fluorescence-based binding experiments.

2. Cell-Surface Imaging

Sulfo-Cy3-Methyltetrazine supports fluorescent visualization of cell-surface targets in experiments built around TCO pre-installation on cell-associated biomolecules. In common lab use, researchers label TCO-bearing cells or cell-surface constructs with the Cy3 tetrazine reagent to generate red fluorescence for tracking binding, uptake, or spatial distribution using fluorescence microscopy. Its bioorthogonal click labeling format helps minimize background from nonspecific dye conjugation steps, which is particularly valuable when comparing localization patterns across conditions in receptor-binding and cell-interaction studies.

3. Fluorescent Probe Construction

Sulfo-Cy3-Methyltetrazine is frequently employed in fluorescence probe development to generate Cy3-labeled imaging reagents from TCO-functional building blocks. Probe developers use it to assemble modular multicomponent constructs such as fluorescent affinity probes, labeling reagents for biomaterial-associated components, and imaging conjugates for microscopy workflows. The combination of a Cy3 fluorophore with a tetrazine click handle enables straightforward late-stage incorporation of the fluorescent reporter, supporting consistent probe synthesis strategies for screening experiments where fluorophore placement and labeling density are important for imaging contrast.

4. Biomaterial Surface Functionalization

Sulfo-Cy3-Methyltetrazine is used in biomaterials research to fluorescently decorate TCO-functional surfaces, hydrogels, and polymer constructs for visualization and material-interface studies. Materials scientists and tissue engineering groups incorporate TCO groups into the substrate or coating layer and then apply the tetrazine Cy3 reagent to introduce a red fluorescent reporter for confirming surface coverage, spatial patterning, and stability of functional layers. This approach is commonly used to support experimental design for imaging-based characterization of engineered materials, including monitoring how functional coatings distribute across complex surfaces.