sulfo-Cyanine3 streptavidin

Sulfo-Cyanine3 streptavidin is a fluorescently labeled streptavidin conjugate designed for high-affinity biotin-based capture and visualization in fluorescence workflows. The sulfonated cyanine dye supports aqueous labeling applications, enabling bright detection of biotinylated targets while maintaining compatibility with common fluorescence imaging and plate-based assays. This reagent is frequently used as a modular detection layer for biotin-tagged biomolecules, affinity reagents, and nucleic-acid constructs where robust streptavidin-biotin binding drives signal localization.

1. Biotinylated Biomolecule Detection

Sulfo-Cyanine3 streptavidin is used to visualize and quantify biotinylated proteins, peptides, and other affinity-tagged biomolecules in fluorescence-based assays. Researchers commonly employ it as a fluorescent detection reagent in binding studies, pull-down workflows, and assay development where the streptavidin component provides strong capture of biotinylated targets and the cyanine dye provides direct optical readout. The water-soluble sulfonated dye format helps maintain performance in aqueous buffers used for conjugate handling and washing steps, supporting workflows such as endpoint fluorescence measurements and imaging of labeled complexes.

2. Fluorescence Microscopy Labeling

Sulfo-Cyanine3 streptavidin enables fluorescent staining of biotinylated samples for cellular and molecular microscopy experiments. In practice, it is often used to label biotinylated antibodies, ligands, or secondary reagents to generate cyanine-based fluorescence contrast in fixed-cell imaging and biomolecular localization studies. Because streptavidin binds biotin with high affinity, the reagent is frequently selected for multistep labeling schemes where a consistent fluorescent detection layer is needed after biotin incorporation onto the target of interest.

3. Flow Cytometry Signal Readout

Sulfo-Cyanine3 streptavidin is commonly applied as a fluorescent labeling reagent for flow cytometry experiments that rely on biotin-tagged binding reagents. In these workflows, biotinylated antibodies or other affinity constructs are incubated with cells or bead-bound targets, followed by fluorescent streptavidin labeling to generate a measurable fluorescence signal by flow cytometric analysis. The cyanine dye labeling format supports routine cytometry workflows that include washing and gating to distinguish labeled populations, making the reagent useful for receptor-binding studies, biomolecule binding assays, and bead-based binding readouts.

4. Nucleic Acid Probe Visualization

Sulfo-Cyanine3 streptavidin is used to generate fluorescent readouts for biotinylated nucleic-acid constructs, including biotin-tagged oligonucleotides and nucleic-acid probes used in hybridization workflows. Researchers often incorporate biotin into probe strands and then use the fluorescent streptavidin conjugate to visualize hybridization products or to label nucleic-acid-containing complexes on gels, membranes, or imaging platforms. This approach supports assay development where a stable fluorescent detection layer is required after target capture, leveraging the strong streptavidin-biotin interaction to localize the cyanine signal to the nucleic-acid-containing fraction.