Sulfo-Cyanine5 Carboxylic Acid (ethyl) Potassium Salt(1:1) | CAS 449175-58-0

Sulfo-Cyanine5 Carboxylic Acid (ethyl) Potassium Salt(1:1) is a water-soluble, sulfonated cyanine dye designed for fluorescent labeling workflows where bright far-red emission and aqueous compatibility are important. Its carboxylic acid functionality supports conjugation to amine-bearing biomolecules and labeling platforms commonly used in fluorescence microscopy, flow cytometry, and fluorescence-based bioassays. Researchers often select this dye when they need robust far-red signal for multicolor experiments and imaging readouts.

1. Protein And Antibody Labeling

Sulfo-Cyanine5 Carboxylic Acid (ethyl) Potassium Salt(1:1) is frequently used to generate far-red fluorescent protein conjugates for immunofluorescence and targeted binding studies. Typical workflows involve coupling the dye to antibodies, antibody fragments, or other amine-containing proteins to produce fluorescent immunoreagents for imaging and assay development. The sulfonated cyanine scaffold helps maintain solubility in aqueous buffers, which supports routine labeling and downstream handling in microscopy chambers and plate-based fluorescence formats.

2. Fluorescence Microscopy Staining

Sulfo-Cyanine5 Carboxylic Acid (ethyl) Potassium Salt(1:1) is well suited for cellular and biomaterial fluorescence microscopy applications where far-red channels reduce spectral overlap with common green fluorophores. Researchers use dye-conjugated targeting reagents to visualize binding patterns on cells, extracellular matrices, and labeled biomaterial surfaces. In practice, the dye is incorporated into labeling strategies that rely on stable fluorescent conjugates for endpoint imaging, including multicolor staining panels where cyanine emission in the red/far-red region is advantageous.

3. Flow Cytometry Fluorescent Labeling

Sulfo-Cyanine5 Carboxylic Acid (ethyl) Potassium Salt(1:1) supports flow cytometry workflows that require a far-red fluorescence label for population analysis and multicolor gating strategies. Conjugates prepared with this dye are commonly used to stain cell-surface proteins or other amine-functional targets, enabling quantitative fluorescence readouts by standard flow cytometers equipped with appropriate far-red excitation and detection optics. The dye's water solubility and conjugation-ready carboxylate functionality help streamline reagent preparation for reproducible staining and instrument-compatible measurements.

4. Fluorescent Bioassay Development

Sulfo-Cyanine5 Carboxylic Acid (ethyl) Potassium Salt(1:1) is used in fluorescence assay development as a labeling component for assay reagents and detection conjugates. In plate-based formats, the dye-labeled biomolecules can serve as fluorescent reporters in binding assays, labeling-based readouts, and reagent controls that benefit from far-red emission. Teams developing fluorescence standards and assay calibration materials also rely on cyanine dyes like this one to generate consistent fluorescent reagents for method development and assay optimization.