Used in bioorthogonal chemistry for labeling biomolecules in live systems. Its strained cyclooctyne group reacts rapidly with azides via copper-free click chemistry, making it ideal for imaging and tracking biomolecules without interfering with biological processes. The PFP ester group enables stable conjugation to primary amines on proteins, peptides, or other amine-containing molecules. Commonly applied in fluorescent labeling, drug discovery, and development of bioconjugates for diagnostics and targeted therapies. Stable under physiological conditions, allowing for efficient labeling in complex environments.