Sulfo-Cy7 ethylenediamine is widely used in the field of biomedical imaging and diagnostics due to its near-infrared (NIR) fluorescence properties. Its ability to emit light in the NIR range makes it ideal for in vivo imaging, as NIR light penetrates tissues more deeply and with less background interference compared to visible light. This compound is commonly employed in labeling proteins, peptides, and antibodies for tracking and visualization in biological systems. It is particularly useful in cancer research for tumor targeting and imaging, as well as in studying cellular processes and molecular interactions. Additionally, its water solubility enhances its applicability in physiological environments, making it a valuable tool for fluorescence microscopy, flow cytometry, and small animal imaging studies.