Cy7 is widely used in biomedical research as a near-infrared fluorescent dye due to its deep tissue penetration and minimal background interference. It is commonly employed in imaging techniques for tracking cells, proteins, and other biomolecules in vivo. Cy7-labeled antibodies and peptides are utilized in immunofluorescence and flow cytometry for detecting specific targets. Additionally, it is applied in molecular imaging for studying tumor progression, drug delivery, and gene expression. Its stability and brightness make it a preferred choice for non-invasive diagnostic and therapeutic applications.