Cyanine3 NHS ester tetrafluoroborate | CAS 2632339-91-2

Cyanine3 NHS ester is a reactive cyanine dye designed for covalent fluorescent labeling via N-hydroxysuccinimide (NHS) ester chemistry. The dye's bright visible emission makes it widely used for fluorescence microscopy and fluorescence-based assays where robust fluorescent tagging of biomolecules is required. Its NHS ester functionality enables straightforward conjugation to primary amines on proteins, peptides, and other amine-containing targets.

1. Protein And Antibody Labeling

Cyanine3 NHS ester is frequently used to generate fluorescently labeled proteins and antibodies for imaging and binding studies. Researchers typically conjugate the NHS ester to lysine residues and N-termini to create amine-reactive cyanine3 conjugates used in fluorescence microscopy, fluorescence-based binding assays, and immunolabeling workflows. This labeling approach is especially common when a stable covalent dye attachment is preferred for multi-step staining or wash-intensive protocols.

2. Fluorescence Microscopy Staining

Cyanine3 NHS ester supports fluorescent staining workflows for cellular and biomolecular imaging where a red/orange-emitting cyanine dye provides clear visual contrast. In microscopy applications, the dye is commonly incorporated into labeled antibodies, affinity reagents, or protein probes to visualize targets with fluorescence readout using standard fluorescence microscope filter sets appropriate for cyanine3 emission. The NHS ester chemistry is also used to prepare labeled biomolecular standards for imaging experiments that require consistent dye-to-protein conjugates.

3. Flow Cytometry Labeling Reagents

Cyanine3 NHS ester is employed in the development of flow cytometry labeling reagents by producing cyanine3-conjugated proteins that can be used as fluorescent tags in cell-surface or intracellular staining panels. Typical workflows involve conjugating the NHS ester to amine-containing targeting reagents such as antibodies or protein ligands, followed by buffer exchange and formulation for staining. The resulting cyanine3 conjugates enable fluorescence detection on flow cytometers using appropriate excitation/emission channels for cyanine3.

4. Fluorescent Bioassay Conjugates

Cyanine3 NHS ester is widely used to prepare fluorescent conjugates for fluorescence readouts in bioassay development, including binding assays and reagent labeling for assay platforms that rely on covalent dye tagging. By labeling amine-containing assay components, the dye can be incorporated into detection reagents used to monitor binding events, wash steps, or signal generation in plate-based fluorescence assays. This makes the reagent useful for constructing assay-specific fluorescent reagents where consistent covalent attachment of the dye to the assay component is required.