IRDye® 650 Azide

IRDye® 650 Azide is a far-red fluorescent labeling reagent built around the IRDye® 650 fluorophore and functionalized with an azide group for copper-catalyzed azide-alkyne cycloaddition (CuAAC). In bioconjugation workflows, the azide handle enables efficient attachment to alkyne-bearing biomolecules, linkers, and surfaces, supporting fluorescence microscopy, imaging, and quantitative fluorescence readouts where reduced autofluorescence from the visible range is advantageous.

1. Biomolecule Labeling

IRDye® 650 Azide is used to generate fluorescently tagged proteins, peptides, and other biomolecules via click chemistry with alkyne-functional partners. Researchers commonly incorporate the azide dye into labeling strategies for antibody conjugates, affinity reagents, and protein probes where far-red emission improves visualization against background. The resulting IRDye® 650 conjugates are frequently used in fluorescence imaging workflows, including gel-based fluorescence readouts and imaging of labeled biomolecular complexes.

2. Fluorescence Microscopy Imaging

IRDye® 650 Azide supports cellular and molecular imaging experiments where far-red fluorescence helps reduce interference from endogenous fluorophores. By clicking the azide dye onto alkyne-modified targeting ligands or biomolecular markers, users can produce microscopy-ready conjugates for tracking labeled structures, studying biomolecular localization, and visualizing tagged components in fixed or prepared samples. The dye's far-red spectral region is particularly useful in multicolor experiments that include visible-channel fluorophores, allowing separation of emission bands during image acquisition.

3. Flow Cytometry Conjugates

IRDye® 650 Azide is employed to prepare far-red flow cytometry reagents through click labeling of alkyne-bearing antibodies, binders, or labeling scaffolds. In instrument workflows that include far-red detection channels, the azide handle enables consistent conjugation to create fluorescent conjugates for cell-surface or intracellular labeling strategies after appropriate biomolecule delivery and staining steps. Researchers use these IRDye® 650 conjugates to quantify labeled populations by fluorescence intensity while minimizing spectral overlap with common green/orange dyes.

4. Surface And Materials Functionalization

IRDye® 650 Azide is also used for fluorescent tagging of biomaterials and engineered surfaces by coupling to alkyne-functional coatings, linkers, or immobilized capture layers. Materials scientists and chemical biology teams incorporate the dye into surface modification workflows to create fluorescently traceable materials, assay platforms, and labeling reagents for microscopy and imaging-based characterization. Far-red emission makes the resulting labeled surfaces useful for monitoring adsorption, binding, and spatial distribution in experimental setups where visible staining would contribute higher background.