IRDye® 800RS NHS Ester | CAS 918324-94-4

IRDye® 800RS NHS Ester is an N-hydroxysuccinimide (NHS) ester-activated near-infrared fluorophore designed for covalent fluorescent labeling of primary amine-containing biomolecules. The IRDye 800RS dye is typically excited in the near-infrared region and is used in fluorescence imaging workflows where reduced background from biological autofluorescence is advantageous. In practice, this reagent is commonly used to prepare labeled antibodies, proteins, peptides, and other amine-functional targets for imaging, binding studies, and quantitative fluorescence readouts.

1. Antibody Conjugation

IRDye® 800RS NHS Ester is widely used to generate near-infrared fluorescent antibody conjugates for immunofluorescence microscopy, western blot-style fluorescence detection, and fluorescence-based binding assays. Researchers and assay developers use the NHS ester to label lysine residues on antibodies, enabling direct tracking of antigen-antibody interactions and localization in fixed samples or in imaging platforms that accept far-red/near-infrared excitation and emission. Because the labeling is covalent, the resulting conjugates are well suited to workflows that include washing steps and quantitative imaging of labeled targets.

2. Protein and Peptide Labeling

IRDye® 800RS NHS Ester supports fluorescent labeling of proteins and peptides for molecular imaging reagent development and biochemical assay development. In protein chemistry and chemical biology labs, the reagent is used to prepare amine-reactive fluorescent conjugates for monitoring binding, uptake, or distribution in fluorescence imaging experiments, including studies where near-infrared dyes help reduce interference from visible-range fluorophores. The NHS-ester functionality also makes it a common choice for preparing labeled standards and tracer reagents used to quantify fluorescence intensity across experimental conditions.

3. Flow Cytometry NIR Labeling

IRDye® 800RS NHS Ester is used to prepare fluorescent labeling reagents for flow cytometry panels that incorporate near-infrared detection channels. Flow cytometry users typically conjugate the dye to antibodies or other amine-bearing targeting ligands to generate NIR dyes for multiplex immunophenotyping, where spectral separation from common fluorophores can improve panel design flexibility. The covalent NHS-ester chemistry helps produce stable conjugates for staining workflows that require reproducible signal across samples and instrument runs.

4. In Vivo Imaging Reagent Development

IRDye® 800RS NHS Ester is frequently used in the development of near-infrared imaging reagents for preclinical fluorescence imaging research workflows, including preparation of fluorescent tracers and targeting conjugates. Researchers conjugate the dye to targeting proteins or other amine-functional ligands to create imaging probes intended for optical readout in near-infrared channels. This application is particularly common when investigators want a fluorescent label that performs in the far-red/near-infrared region commonly used for whole-body or deep-tissue optical imaging setups.