N-Methyl-N'-(hydroxy-PEG2)-Cy5 is widely used in biomedical research for labeling and imaging purposes. Its Cy5 fluorophore enables high-sensitivity fluorescence detection, making it ideal for tracking biomolecules in live cells or tissues. The PEG2 spacer enhances solubility and reduces nonspecific interactions, improving the performance of the dye in complex biological environments. It is commonly employed in fluorescence microscopy, flow cytometry, and in vivo imaging studies to visualize cellular processes, protein interactions, and drug delivery systems. Additionally, its conjugation capabilities allow it to be attached to antibodies, peptides, or other targeting molecules, facilitating specific detection of biological targets.