Carboxyrhodamine 110-PEG4-DBCO

Carboxyrhodamine 110-PEG4-DBCO is a rhodamine 110-based fluorescent labeling reagent bearing a carboxyl group for conjugation to amines and a DBCO (dibenzocyclooctyne) group for strain-promoted azide-alkyne cycloaddition. The PEG4 spacer supports bioconjugation and reduces steric constraints, enabling efficient attachment of the dye to azide-functional biomolecules, surfaces, and biomaterials for fluorescence imaging and probe construction. Its rhodamine 110 fluorescence is widely used in labeling workflows where sensitive, bright detection is required.

1. Biomolecule Labeling

Carboxyrhodamine 110-PEG4-DBCO is used to generate fluorescent bioconjugates for tracking proteins, peptides, and other biomolecules in chemical biology workflows. Researchers typically prepare azide-functional targets (for example, via azide-bearing linkers or azide-tagged biomolecules) and then attach the DBCO dye to produce a stable fluorescent conjugate for downstream microscopy, gel-based fluorescence readouts, or fluorescence imaging of labeled samples. The combination of a PEG4 linker and the dye's carboxyl handle supports flexible conjugate design, including further coupling to amine-containing biomolecules when a two-step labeling strategy is required.

2. Fluorescent Probe Construction

Carboxyrhodamine 110-PEG4-DBCO serves as a practical fluorophore building block for fluorescent probe development, particularly when a modular attachment strategy is needed. In probe construction, the DBCO group enables click-style installation onto azide-bearing recognition elements such as affinity reagents, targeting ligands, or scaffold materials, allowing rapid assembly of imaging reagents without requiring catalysts. The rhodamine 110 fluorophore provides a strong fluorescence signal for visualization, while the carboxyl functionality allows incorporation into probe formats that require additional conjugation chemistry or controlled attachment density.

3. Surface And Biomaterial Functionalization

Carboxyrhodamine 110-PEG4-DBCO is frequently used to fluorescently label azide-functional surfaces and biomaterials for materials characterization and imaging. By coupling the DBCO dye to azide groups presented on polymer coatings, hydrogels, nanoparticles, or other engineered substrates, researchers can visualize surface coverage, track material distribution, and support fluorescence-based assays that monitor interactions at interfaces. The PEG4 spacer helps maintain dye accessibility after immobilization, which is important for consistent fluorescence readout in microscopy and imaging workflows.

4. Fluorescence Imaging Reagents

Carboxyrhodamine 110-PEG4-DBCO is applied as a labeling reagent for fluorescence imaging studies where a rhodamine 110 fluorophore is advantageous for cellular and molecular visualization experiments. Investigators use the reagent to create fluorescent conjugates for imaging experiments that rely on covalent attachment to azide-containing biomolecular probes or labeling handles introduced into experimental systems. The stable conjugation afforded by DBCO click chemistry supports reproducible imaging reagent preparation for microscopy-based localization studies, fluorescent tracking experiments, and fluorescence readouts in assay development pipelines.