Cy5.5 DBCO | CAS 1857352-95-4

Cy5.5 DBCO is a near-infrared fluorescent cyclooctyne bearing a DBCO (dibenzocyclooctyne) functional group, designed for strain-promoted azide–alkyne cycloaddition (SPAAC) click chemistry. The reagent couples a highly photostable Cy5.5 fluorophore to a bioorthogonal cyclooctyne handle, enabling rapid labeling of azide-containing biomolecules and materials under mild conditions. Cy5.5 DBCO is widely used in chemical biology and molecular imaging workflows where fluorescent tagging, multicolor probe development, and click-based surface or polymer functionalization are required.

1. Live-Cell Imaging Probes

Cy5.5 DBCO is commonly used to generate fluorescent imaging probes for cell-based assays and microscopy studies that rely on bioorthogonal click labeling of azide-tagged targets. Researchers incorporate azide groups into proteins, peptides, glycans, or nucleic-acid analogs, then use Cy5.5 DBCO to install the Cy5.5 near-infrared signal with minimal perturbation and without the need for copper catalysts. This labeling strategy supports time-resolved experiments, wash-and-image workflows, and compatibility with multiplexed fluorescence panels where Cy5.5 emission is selected to reduce spectral overlap.

2. Protein and Biomolecule Labeling

Cy5.5 DBCO serves as a versatile reagent for post-modification of azide-functional biomolecules, including engineered proteins, antibody fragments, enzyme conjugates, and affinity reagents. In typical research pipelines, azide handles are introduced through site-specific or random azidation strategies, and Cy5.5 DBCO is then used to attach the Cy5.5 fluorophore for tracking, quantification, and downstream assay development. The DBCO click handle is particularly valued in biochemical workflows that require fast conjugation, robust labeling, and straightforward integration into existing bioconjugation schemes.

3. NIR Molecular Imaging Reagents

Cy5.5 DBCO is frequently selected for constructing near-infrared fluorescent imaging reagents used in optical imaging and fluorescence-guided characterization of labeled constructs. By clicking Cy5.5 onto azide-bearing targeting ligands, imaging scaffolds, or imaging-compatible polymers, teams can tailor probe brightness and spectral properties to match NIR detection hardware. The Cy5.5 fluorophore combined with SPAAC labeling makes Cy5.5 DBCO a practical building block for generating imaging-ready conjugates for assay development, instrument optimization, and probe comparison studies.

4. Functionalized Surfaces and Materials

Cy5.5 DBCO is applied to fluorescently label azide-functionalized materials, including polymer coatings, hydrogel networks, and biomaterial surfaces, enabling visualization of material chemistry and spatial patterning. Materials scientists and biomaterials teams often incorporate azide groups into the substrate or into pendant polymer side chains, then use Cy5.5 DBCO to install the fluorescent reporter via SPAAC. This approach supports mapping of surface functionalization, monitoring of conjugation density in material batches, and development of fluorescently trackable scaffolds for research-grade biomaterials characterization.