Acid-Cy7-NHS ester

Acid-Cy7-NHS ester is a reactive Cy7-family near-infrared fluorescent dye supplied as an NHS ester, enabling efficient covalent labeling of primary amines on proteins, peptides, and other amine-containing biomolecules. Its long-wavelength emission supports low-background fluorescence imaging workflows where red/NIR detection is preferred, and the dye's activated ester form makes it well matched to conjugate preparation for microscopy, imaging, and fluorescence-based assays.

1. Protein Conjugate Labeling

Acid-Cy7-NHS ester is widely used by bioconjugation groups to generate fluorescently labeled proteins and antibody conjugates for NIR imaging and fluorescence-based readouts. Researchers typically employ the NHS ester to attach the dye to lysine residues on target proteins, producing stable amide-linked conjugates that can be used in binding studies, tracer experiments, and imaging reagent development. The Cy7 spectral region is particularly useful when background autofluorescence is a concern, such as in complex biological samples or when multiplexing with visible fluorophores.

2. Fluorescence Imaging Probes

Acid-Cy7-NHS ester supports the construction of NIR fluorescence imaging probes for cellular and molecular imaging workflows in microscopy and whole-sample imaging setups that detect in the red/NIR range. Conjugates prepared from amine-bearing targeting scaffolds, such as peptides, protein binders, or other biomolecular carriers, are used to visualize localization and distribution in imaging experiments. In these applications, the NHS ester functionality simplifies probe generation by providing a direct route to covalent dye conjugation, enabling consistent probe handling compared with noncovalent staining approaches.

3. Biomolecule Tracking Assays

Acid-Cy7-NHS ester is used to prepare fluorescent tracers for quantitative fluorescence assays where covalent labeling improves assay robustness and reduces dye loss during washing or incubation steps. Conjugates derived from amine-containing biomolecules are commonly incorporated into binding/interaction assays, uptake or transport studies, and reagent development for fluorescence readouts that benefit from NIR excitation/emission detection. The activated NHS ester format helps streamline conjugate generation for assay development teams working with proteinaceous reagents and standardized labeling workflows.

4. Surface Coating And Immobilization

Acid-Cy7-NHS ester is also applied in biomaterials and surface functionalization workflows to introduce NIR fluorescence onto amine-rich surfaces and coatings. Researchers use the NHS ester to covalently attach the dye to amine-bearing polymers, hydrogel matrices, or other functional materials that present primary amines, creating fluorescently trackable surfaces for material characterization and imaging. This approach is useful when fluorescence labeling needs to remain associated with a solid support during handling, incubation, or repeated imaging.