ROX NHS ester, 6-isomer | CAS 117491-83-5

ROX NHS ester, 6-isomer is a reactive N-hydroxysuccinimide (NHS) ester fluorophore designed for covalent fluorescent labeling of primary amines on proteins, peptides, and other amine-containing biomolecules. Its ROX spectral profile makes it a common choice for red-channel fluorescence workflows, including microscopy and fluorescence-based assays where robust labeling chemistry is needed. Because the NHS ester reacts efficiently under standard protein-labeling conditions, it is widely used to prepare fluorescent conjugates for downstream imaging, quantification, and assay development.

1. Protein And Antibody Labeling

ROX NHS ester, 6-isomer is frequently used by cell biology and analytical chemistry groups to generate fluorescently labeled proteins and antibodies for binding and uptake studies. Researchers typically target lysine residues and N-termini to produce stable amine-to-ester coupling conjugates that can be introduced into microscopy experiments, flow cytometry panels, or fluorescence-based binding assays. This reagent format is particularly convenient when a red-emitting dye is desired for multicolor experiments or when compatibility with common red-channel filter sets is required.

2. Fluorescent Peptide Conjugates

ROX NHS ester, 6-isomer supports preparation of fluorescent peptide conjugates used in receptor-binding characterization, ligand tracking, and biomolecular interaction studies. By labeling peptides that contain accessible primary amines, researchers can create fluorescent ligands for localization experiments and for quantifying binding in plate-based fluorescence assays. The NHS-ester coupling approach is also commonly used during probe development when a defined, amine-reactive handle is needed to attach a ROX fluorophore to a targeting scaffold.

3. Oligonucleotide And Nucleic Acid Labeling

ROX NHS ester, 6-isomer is used to introduce a ROX fluorophore onto nucleic-acid-related constructs that present primary amine groups, such as amine-modified oligonucleotides, aminated linkers, or nucleic-acid conjugates used in hybridization workflows. In these applications, the labeled strands or conjugates serve as fluorescent reporters for nucleic acid detection methods, nucleic acid binding studies, and fluorescence readouts in assay development. The reactive NHS-ester chemistry enables straightforward incorporation of a red-emitting dye into nucleic acid probe formats.

4. Biomaterial Surface Functionalization

ROX NHS ester, 6-isomer is also applied in biomaterials research to fluorescently tag amine-functionalized surfaces and scaffolds, enabling visualization of coating uniformity, surface adsorption, and material-cell interactions. Investigators commonly use the NHS-ester reactivity to covalently immobilize ROX onto amine-bearing polymers, hydrogels, or surface coatings, then track the labeled materials by fluorescence microscopy or other imaging readouts. This approach is valuable when a stable, covalent fluorescent marker is required for qualitative and semi-quantitative surface studies.