Fluorescein isothiocyanate (FITC) is widely used in biological research as a fluorescent dye for labeling proteins, antibodies, and other biomolecules. Its ability to bind covalently to amino groups makes it a valuable tool in fluorescence microscopy, flow cytometry, and immunofluorescence assays. FITC-labeled antibodies are commonly employed to detect specific antigens in cells or tissues, enabling researchers to visualize and analyze cellular structures and processes. Additionally, FITC is used in diagnostic applications, such as detecting pathogens or monitoring immune responses. Its bright green fluorescence under UV light makes it a popular choice for tracking and imaging in various scientific studies.