N,N'-bis-(azide-PEG3)-Cy5 | CAS 2107273-46-9

N,N'-bis-(azide-PEG3)-Cy5 is a Cy5-based fluorescent labeling building block bearing two azide groups separated by PEG3 linkers, enabling efficient azide participation in strain-promoted or copper-catalyzed azide-alkyne click conjugation workflows. The Cy5 chromophore provides red fluorescence for imaging and assay development, while the PEG spacers help maintain conjugate flexibility and reduce steric constraints during biomolecule, polymer, or surface functionalization. This reagent is commonly used to generate fluorescent conjugates where azide handles are required for modular attachment to targeting ligands, biomacromolecules, or materials.

1. Biomolecule Labeling

N,N'-bis-(azide-PEG3)-Cy5 is frequently used by chemical biology and glycobiology labs to prepare fluorescently labeled proteins, peptides, and other biomacromolecules through click conjugation to alkyne-functional partners. Researchers leverage the dual-azide architecture to tune labeling density and multivalency, which is useful when building fluorescent affinity reagents, imaging probes, or assay standards. The PEG3 spacing supports flexible presentation of the Cy5 dye, helping maintain labeling performance in conjugates used for fluorescence microscopy and fluorescence-based binding studies.

2. Click-Constructed Imaging Probes

N,N'-bis-(azide-PEG3)-Cy5 serves as a modular component for constructing multi-component fluorescent imaging reagents, including conjugates that combine a Cy5 reporter with targeting motifs introduced via click chemistry. In probe development workflows, the azide groups provide a convenient attachment point to alkyne-bearing targeting ligands, such as affinity peptides or other biomolecular handles, enabling researchers to rapidly assemble and compare probe formats. This approach is widely used in fluorescence imaging method development where consistent Cy5 reporting is required while varying the targeting or scaffold architecture.

3. Polymer And Surface Functionalization

N,N'-bis-(azide-PEG3)-Cy5 is also applied in biomaterials and surface chemistry to introduce Cy5 fluorescence onto polymeric materials, hydrogels, and engineered surfaces using azide-alkyne click coupling. Materials scientists use the PEG3-linked azide groups to incorporate fluorescent tags into functional coatings or to create fluorescently traceable materials for microscopy, material tracking, and process monitoring in research settings. The dual azide functionality can support crosslinking or multivalent grafting strategies when paired with appropriately functionalized alkyne surfaces or polymer networks.