Cyanine5.5 tetrazine

Cyanine5.5 tetrazine is a tetrazine-functionalized cyanine fluorophore designed for strain-promoted inverse electron-demand Diels-Alder (SPIEDAC) click chemistry. This dye combines a bright, far-red/near-infrared-leaning emission profile with the highly reactive tetrazine handle, enabling rapid labeling of biomolecules, probes, and material surfaces under bioorthogonal conditions. In fluorescent conjugate workflows, Cyanine5.5 tetrazine is used as a tetrazine-tagged imaging reagent that delivers covalently attached far-red fluorescence for microscopy, flow cytometry, and fluorescence-based assay development.

1. Biomolecule Labeling

Cyanine5.5 tetrazine is widely used to fluorescently label proteins, peptides, and other biomolecular reagents in chemical biology workflows where covalent attachment and defined stoichiometry are important. Researchers attach the tetrazine dye to complementary cyclooctene/strained-alkene partners (introduced on antibodies, affinity ligands, or engineered biomolecules) to generate stable fluorescent conjugates for cellular imaging, binding studies, and reagent tracking. The cyanine dye format supports sensitive visualization in far-red channels, making it a common choice when spectral separation from green/orange fluorophores is required.

2. Fluorescent Probe Construction

Cyanine5.5 tetrazine serves as a key building block for constructing fluorescent probes and multicomponent imaging reagents that require modular assembly. In probe development, the tetrazine handle enables late-stage conjugation to targeting scaffolds (such as affinity vectors or probe backbones) bearing a cyclooctene motif, allowing teams to swap targeting elements without redesigning the fluorophore. This approach is frequently used to produce microscopy-ready conjugates, fluorescent standards for assay calibration, and imaging reagents for platform validation where consistent far-red signal reporting is needed.

3. Surface Functionalization

Cyanine5.5 tetrazine is used to incorporate far-red fluorescence onto biomaterials and engineered surfaces through bioorthogonal click immobilization strategies. Materials scientists and biomaterials researchers apply the tetrazine dye to surfaces or particles that present cyclooctene-functional groups, producing fluorescently labeled hydrogels, nanoparticles, and polymer coatings for tracking, localization, and material characterization. The covalent attachment helps reduce dye leaching during washing steps common to imaging and analytical workflows, supporting reproducible readouts in microscopy and fluorescence-based characterization.

4. Multiplex Fluorescence Assays

Cyanine5.5 tetrazine is employed in fluorescence assay development where far-red emission provides convenient multiplexing with other fluorophores. Assay developers use tetrazine click labeling to generate fluorescent conjugates for binding assays, labeling controls, and reagent normalization standards, particularly when assay panels include multiple spectral channels. The tetrazine chemistry supports workflow designs that separate conjugate preparation from assay execution, helping teams streamline reagent generation for plate-based fluorescence measurements and comparative studies across experimental conditions.