Cyanine5.5 amine is widely used as a fluorescent dye in various biological and medical research applications. Its near-infrared fluorescence makes it particularly useful for in vivo imaging, as it allows for deep tissue penetration with minimal background interference. This dye is commonly conjugated to antibodies, peptides, or other biomolecules to enable targeted imaging of specific cells or tissues, such as in cancer research for tumor detection and monitoring. It is also employed in flow cytometry and fluorescence microscopy to study cellular processes and interactions. Additionally, Cyanine5.5 amine is utilized in the development of diagnostic tools and therapeutic agents, where its stable and bright fluorescence aids in tracking drug delivery and evaluating treatment efficacy.