sulfo-Cyanine3.5 amine

Sulfo-Cyanine3.5 amine is a water-soluble cyanine dye in the bright cyanine family, supplied with an amine handle for straightforward conjugation to biomolecules and labeling platforms. Its sulfonated character supports aqueous workflows used in fluorescence labeling, while the reactive amine enables attachment to NHS-ester-activated surfaces, crosslinkers, or other coupling strategies commonly used in fluorescence microscopy and assay development. Researchers leverage this dye to build fluorescent conjugates where strong visible excitation/emission performance and aqueous compatibility are required.

1. Protein And Antibody Labeling

Sulfo-Cyanine3.5 amine is used to generate fluorescent protein conjugates for binding studies, imaging reagents, and fluorescence-based bioassays. Bioconjugation teams typically incorporate the dye into antibody or protein labeling workflows to produce Cy3.5-like reporters that can be tracked in aqueous buffers during incubation, washing, and readout steps. The sulfonated dye format helps maintain solubility in labeling and assay conditions, supporting consistent staining of target biomolecules in microscopy and plate-based fluorescence experiments.

2. Fluorescence Microscopy Staining

Sulfo-Cyanine3.5 amine supports cellular and biomolecular fluorescence imaging where a cyanine dye reporter is needed for localization studies. Imaging groups use dye-labeled probes and conjugates to visualize labeled targets in fixed samples or in buffer-based microscopy workflows, often coupling the dye to targeting ligands or affinity reagents prior to imaging. The amine functionality enables incorporation into labeling schemes used to prepare fluorescent conjugates for slide-based imaging, including multi-step staining workflows where aqueous compatibility and robust fluorescence in the visible range are important.

3. Flow Cytometry Conjugates

Sulfo-Cyanine3.5 amine is applied in the preparation of fluorescent conjugates for flow cytometry experiments that require a cyanine dye signal for population gating and labeling readouts. Researchers typically use the dye in conjugation pipelines to generate antibody or ligand conjugates that report on binding to cell-surface or biomolecular targets during staining and washing. The water-soluble sulfonated dye format is particularly helpful for maintaining dye performance in aqueous cytometry buffers and for supporting reproducible fluorescence labeling across experimental runs.

4. Fluorescent Probe Development

Sulfo-Cyanine3.5 amine is frequently incorporated into fluorescent probe and reagent development programs where a cyanine fluorophore is required as a detectable reporter. Chemical biology and assay development teams use the amine handle to construct labeled reagents for tracking biomolecular interactions, monitoring binding events, or building fluorescence readout components for custom assay formats. In these workflows, the dye's aqueous compatibility and conjugation-ready amine functionality help streamline reagent construction for downstream fluorescence measurements in microplate readers and imaging systems.