This compound is widely used in bioconjugation and chemical biology for linking molecules, particularly in the modification of proteins, peptides, and other biomolecules. Its NHS ester group enables efficient coupling with primary amines, while the Boc-protected aminooxy group allows for subsequent deprotection and reaction with carbonyl-containing compounds, such as ketones or aldehydes. This makes it valuable in the development of antibody-drug conjugates, targeted drug delivery systems, and the study of biomolecular interactions. Additionally, the PEG4 spacer enhances solubility and reduces steric hindrance, improving the efficiency of conjugation processes. It is also employed in the synthesis of bioconjugates for diagnostic and therapeutic applications.