Sulfo-Cy5.5 cadaverine is widely used in fluorescence labeling and imaging applications, particularly in biological and biomedical research. Its near-infrared fluorescence properties make it ideal for in vivo imaging, as it allows deep tissue penetration with minimal background interference. This compound is commonly employed to label proteins, peptides, and other biomolecules, enabling researchers to track their distribution, interaction, and dynamics in live cells or animal models. Additionally, it is utilized in molecular probes for diagnostic purposes, such as detecting specific biomarkers in disease studies. Its water solubility further enhances its utility in aqueous biological systems, making it a versatile tool for advanced fluorescence microscopy and imaging techniques.