sulfoCyanine 3 NHS Ester | CAS 1424433-17-9

sulfoCyanine 3 NHS Ester is a water-soluble cyanine dye NHS ester designed for efficient amine-reactive fluorescent labeling. The sulfonate substitution supports aqueous conjugation workflows, while the cyanine fluorophore enables sensitive fluorescence readouts for microscopy and fluorescence-based assays. In bioconjugation, this reagent is commonly used to prepare dye-labeled proteins, peptides, and other primary-amine containing biomolecules for imaging and analytical studies.

1. Protein Fluorescent Labeling

sulfoCyanine 3 NHS Ester is widely used to generate fluorescently labeled proteins for fluorescence microscopy, gel-based tracking, and quantitative fluorescence assays. Researchers typically conjugate the NHS ester to lysine residues on antibodies, enzymes, and affinity reagents to produce stable dye-protein conjugates that retain binding or catalytic activity for downstream characterization. Because the dye is sulfonated, conjugation and handling are often performed in aqueous buffers, supporting routine labeling workflows in chemical biology and protein engineering laboratories.

2. Antibody Conjugation For Imaging

sulfoCyanine 3 NHS Ester supports construction of antibody-fluorophore conjugates used for cellular imaging and immunofluorescence assay development. Imaging groups use the NHS ester to label targeting antibodies or secondary antibodies, enabling visualization of antigen distribution in fixed-cell workflows and fluorescence readouts in microscopy platforms. The resulting cyanine-labeled immunoreagents are also used in assay development where consistent dye loading and aqueous compatibility simplify reagent preparation for research-grade staining and binding studies.

3. Peptide And Biomolecule Tagging

sulfoCyanine 3 NHS Ester is frequently applied to label peptides and other amine-bearing biomolecules used as tracers, affinity ligands, or standards in fluorescence experiments. Chemical biology teams incorporate the dye into peptide-based probes to monitor binding, uptake, or localization in fluorescence imaging and plate-based assays. The NHS ester format allows straightforward coupling to primary amines, supporting preparation of labeled conjugates for biomolecular interaction studies, fluorescence tracking of reagent distribution, and method development in molecular imaging workflows.

4. Fluorescent Assay Reagent Preparation

sulfoCyanine 3 NHS Ester is used to prepare fluorescent assay components such as labeled substrates, detection reagents, and reference standards for fluorescence-based bioassays. Assay developers often conjugate the dye to proteins or other amine-containing reagents to create consistent fluorescent readouts for endpoint measurements and method optimization in microplate formats. In fluorescence quantification workflows, the sulfonated dye helps maintain aqueous compatibility, supporting reproducible reagent handling during assay screening and analytical method development.