Used extensively in biological research as a fluorescent labeling agent. It binds to proteins, antibodies, and other biomolecules, enabling their detection and visualization under fluorescence microscopy. Commonly applied in immunofluorescence assays, flow cytometry, and cell imaging studies. Its isothiocyanate group reacts with amino groups in biomolecules, forming stable thiourea bonds. This makes it a valuable tool for tracking cellular processes, protein interactions, and molecular localization in live or fixed cells. Also utilized in diagnostic applications to identify specific targets in complex biological samples.