Used in bioconjugation processes to link biomolecules such as peptides, proteins, and nucleic acids due to its reactive carboxyl and amino groups. The polyethylene glycol (PEG) spacer enhances solubility and reduces aggregation in biological systems. Commonly applied in drug delivery systems to improve the pharmacokinetics and stability of therapeutic agents. Also utilized in surface modification of nanoparticles and medical devices to increase biocompatibility and reduce immune recognition. Frequently employed in the development of PEGylated reagents for research and diagnostic applications.