Azido-PEG7-CH2COOH is widely used in bioconjugation and click chemistry applications due to its azide functional group, which enables efficient and selective reactions with alkynes via copper-catalyzed azide-alkyne cycloaddition (CuAAC). This compound is particularly valuable in the modification of biomolecules, such as proteins, peptides, and antibodies, for labeling, imaging, or drug delivery purposes. Its polyethylene glycol (PEG) spacer enhances solubility and reduces immunogenicity, making it suitable for use in biological systems. Additionally, the carboxyl group allows for further functionalization, enabling attachment to amine-containing molecules through standard coupling reactions. This chemical is instrumental in the development of targeted therapeutics, diagnostic probes, and advanced materials in biomedical research.