diSulfo-Cy7-bis NHS ester

diSulfo-Cy7-bis NHS ester is a reactive, water-soluble cyanine dye provided as a bis-NHS ester for efficient covalent labeling of primary amine-containing biomolecules. The sulfonated Cy7 framework supports strong near-infrared fluorescence, making it a common choice for sensitive fluorescence imaging and labeling workflows where reduced cellular autofluorescence is advantageous. With two NHS ester groups per dye, it enables multivalent conjugation and higher labeling density for antibody, protein, and other amine-rich targets used in microscopy, imaging, and assay development.

1. Antibody Bioconjugation

diSulfo-Cy7-bis NHS ester is widely used by fluorescence imaging groups to generate near-infrared-labeled antibodies and antibody fragments for immunofluorescence staining, binding studies, and probe construction. Its bis-NHS ester functionality supports covalent attachment to lysine residues on antibodies, enabling robust conjugate preparation for imaging workflows that benefit from Cy7 emission in the far-red/NIR region. Researchers often employ the resulting antibody-Cy7 conjugates to track target binding on cells, in tissue sections, or in protein-biomolecule interaction assays where amine-reactive dyes are preferred.

2. Protein and Peptide Labeling

diSulfo-Cy7-bis NHS ester serves as a labeling reagent for proteins, peptides, and other amine-containing biomolecules used in fluorescence-based bioassays and molecular imaging experiments. The dye's dual NHS ester groups facilitate conjugation to multiple lysines, which can improve labeling density for downstream readouts such as fluorescence microscopy and plate-based imaging assays. Bioconjugation teams commonly use this reagent to prepare fluorescent standards, tracer reagents, and imaging conjugates for method development in chemical biology and biomaterials research.

3. Multivalent Probe Construction

diSulfo-Cy7-bis NHS ester is frequently incorporated into probe and conjugate engineering workflows where multivalent attachment is beneficial, including fluorescent reagent construction for biomolecular detection platforms. By providing two reactive NHS esters, the dye can be used to build conjugates with controlled stoichiometry when reacting with bifunctional amine-containing linkers, carrier proteins, or polymeric scaffolds. Chemical biology and diagnostics reagent developers use these Cy7-based multivalent constructs to create near-infrared fluorescence labeling reagents for imaging readouts and fluorescence-guided experimental workflows.

4. Biomaterial Surface Functionalization

diSulfo-Cy7-bis NHS ester is used in biomaterials and surface chemistry to fluorescently functionalize amine-bearing coatings, hydrogels, and polymer surfaces for imaging and characterization. The bis-NHS ester chemistry enables covalent coupling to surface-accessible primary amines, allowing researchers to generate NIR fluorescent materials for tracking adsorption, coating uniformity, and spatial distribution of functional layers. Materials scientists and interdisciplinary imaging teams often rely on Cy7 fluorescence to visualize labeled surfaces with reduced background in optical imaging experiments.