Used extensively in bioconjugation processes, it serves as a linker molecule to attach polyethylene glycol (PEG) chains to proteins, peptides, or other biomolecules. This modification enhances the stability, solubility, and circulation time of the conjugated molecules in biological systems. It is particularly valuable in pharmaceutical applications, such as PEGylating therapeutic proteins to reduce immunogenicity and prolong their half-life in the body. Additionally, it is employed in research for creating PEGylated probes or drug delivery systems, improving targeting efficiency and reducing side effects. Its reactive N-succinimidyl ester group ensures efficient and specific coupling with amino groups on target molecules.