Cy5 ethylenediamine is widely used in fluorescence labeling and imaging applications. Its strong fluorescence in the near-infrared range makes it ideal for biological studies, such as labeling proteins, nucleic acids, and other biomolecules for visualization in live-cell imaging, flow cytometry, and microscopy. It is particularly useful in multiplex assays due to its distinct emission spectrum, allowing simultaneous detection of multiple targets. Additionally, it is employed in molecular diagnostics, drug discovery, and in vivo imaging, where its stability and brightness enhance sensitivity and accuracy. The ethylenediamine group facilitates conjugation to target molecules, making it a versatile tool in bioresearch and medical diagnostics.