Sulfo-Cyanine5.5 Carboxylic Acid (ethyl) | CAS 210892-23-2

Sulfo-Cyanine5.5 Carboxylic Acid (ethyl) is a sulfonated, water-soluble cyanine dye designed for fluorescent labeling workflows where strong signal in aqueous buffers is required. Its carboxylic acid functionality supports common bioconjugation strategies to attach the dye to proteins, peptides, and other biomolecules used in fluorescence imaging and optical assays. The cyanine scaffold provides absorption and emission well-suited to red/orange fluorescence detection, making it useful for multicolor microscopy and fluorescence readouts.

1. Protein And Peptide Labeling

Sulfo-Cyanine5.5 Carboxylic Acid (ethyl) is frequently used by bioconjugation-focused laboratories to generate fluorescent protein and peptide conjugates for binding and localization studies. Researchers attach the dye to amine- or carboxyl-reactive biomolecule handles during reagent development, then use the resulting conjugates for fluorescence microscopy, fluorescence-based binding assays, and labeling controls in biochemical experiments. The sulfonated structure helps maintain aqueous compatibility, which is particularly useful when conjugates must remain stable and detectable in physiological or assay buffers.

2. Fluorescence Microscopy Tracing

Sulfo-Cyanine5.5 Carboxylic Acid (ethyl) supports cellular and biomaterial tracing experiments where red fluorescence provides clear contrast against common autofluorescence backgrounds. Imaging teams use dye-conjugated biomolecules to visualize transport, uptake, and surface association in microscopy workflows, including fixed-sample studies and imaging of labeled biomaterial components. Its cyanine dye characteristics make it a practical choice for tracking labeled targets in multichannel imaging panels where spectral separation from green fluorophores is needed.

3. Flow Cytometry Labeling Reagents

Sulfo-Cyanine5.5 Carboxylic Acid (ethyl) is used to prepare fluorescence labeling reagents for flow cytometry experiments that require a red-emitting detection channel. Cytometry users conjugate the dye to affinity reagents or biomolecular binders to generate stained samples for analyzing binding behavior, surface association, or labeling efficiency across experimental conditions. The water-soluble sulfonate functionality is advantageous for preparing conjugates that perform reliably in aqueous staining buffers used in routine cytometry workflows.

4. Fluorescent Bioassay Development

Sulfo-Cyanine5.5 Carboxylic Acid (ethyl) is applied in fluorescence assay development where a red fluorophore is needed for optical readouts of labeled reagents and assay components. Assay developers incorporate the dye into biomolecule conjugates used as reporters in binding assays, imaging-compatible biochemical workflows, and fluorescence-based quantification formats. The carboxylic acid functionality enables downstream conjugate construction, allowing the dye to be integrated into custom assay reagents used in research and industrial screening environments.