Sulfo-Cy3 diacid is widely used in biological imaging and fluorescence labeling due to its bright fluorescence and water solubility. It is commonly employed in fluorescence microscopy to visualize and track biomolecules within cells and tissues. This dye is particularly useful in labeling proteins, nucleic acids, and other biomolecules for studies involving cellular processes, protein interactions, and molecular dynamics. Its sulfonate groups enhance solubility in aqueous solutions, making it suitable for live-cell imaging and reducing nonspecific binding. Additionally, Sulfo-Cy3 diacid is used in flow cytometry and immunofluorescence assays, providing high sensitivity and stability for detecting and quantifying target molecules. Its compatibility with various conjugation chemistries allows for versatile applications in biomedical research and diagnostics.