Cy3 is widely used in biological research as a fluorescent dye for labeling and imaging. It is commonly applied in fluorescence microscopy to visualize and track proteins, nucleic acids, and other biomolecules within cells and tissues. Its bright fluorescence and photostability make it ideal for techniques like immunofluorescence, in situ hybridization, and flow cytometry. Cy3 is also utilized in FRET (Förster Resonance Energy Transfer) studies to investigate molecular interactions and conformational changes. Additionally, it serves as a labeling agent in microarray analysis and DNA sequencing, enabling high-sensitivity detection of target molecules. Its compatibility with various biological systems and instruments ensures its versatility in life science applications.