IRDye^® 800CW NHS Ester | CAS 956579-01-4

IRDye® 800CW NHS Ester is an amine-reactive near-infrared fluorescent dye designed for covalent labeling of proteins and other primary-amine containing biomolecules. The NHS ester reacts with lysine residues and N-termini to form stable amide linkages, enabling sensitive fluorescence tracking in imaging and fluorescence-based assays. Its IR emission supports low-background workflows in common fluorescence imaging systems and fluorescence readouts used in chemical biology and biomaterials research.

1. Protein Conjugation Labeling

IRDye® 800CW NHS Ester is widely used to generate near-infrared fluorescent antibody, protein, and peptide conjugates for molecular imaging reagent development. Researchers typically employ the NHS ester to label purified targets such as antibodies, enzymes, growth factors, and affinity reagents, producing well-defined fluorescent conjugates for binding studies, tracer preparation, and workflow validation in imaging experiments. The covalent labeling is particularly valued when stable signal retention is required during washes, incubation steps, or multi-step assay formats used in fluorescence microscopy and plate-based fluorescence measurements.

2. Fluorescence Imaging Tracers

IRDye® 800CW NHS Ester enables preparation of fluorescent tracers for whole-mount and benchtop fluorescence imaging workflows where near-infrared emission helps reduce autofluorescence from biological materials. Chemical biology groups and imaging laboratories use the dye-labeled biomolecules to visualize distribution, uptake, and retention patterns in experimental systems, including labeled ligands used to monitor binding to immobilized targets or cell-associated components. The dye's NHS reactivity also supports rapid conjugate generation for comparative studies, such as evaluating different targeting ligands or optimizing labeling density for imaging readouts on standard near-infrared capable imaging platforms.

3. Biomaterial Surface Functionalization

IRDye® 800CW NHS Ester is used to create fluorescently labeled biomaterial surfaces and coatings by coupling the dye to amine-containing polymers, hydrogel matrices, and protein-functionalized interfaces. Biomaterials researchers incorporate the dye into surface modification workflows to track coating uniformity, quantify surface-associated material, and monitor adsorption or immobilization behavior of functional proteins on engineered substrates. This application benefits from the NHS ester's ability to react with accessible primary amines, allowing researchers to generate stable fluorescent surface markers for microscopy, imaging-based quality control, and fluorescence readouts during material development.

4. Flow Cytometry Labeling

IRDye® 800CW NHS Ester supports fluorescent labeling workflows for flow cytometry when the labeled biomolecule is used as a probe for cell-associated targets or for general fluorescence tracking of labeled reagents. Laboratories commonly conjugate the dye to antibodies or other amine-bearing binding reagents, then use the resulting conjugates to quantify binding to cell populations, assess labeling consistency, or evaluate reagent performance in cell-based assays. The near-infrared emission is leveraged to reduce interference from cellular autofluorescence in multicolor experiments, provided the instrument is configured for the dye's detection channel.