Mal-PEG24-NHS ester is widely used in bioconjugation and protein modification due to its reactive NHS ester and maleimide groups. The NHS ester reacts with primary amines, enabling covalent attachment to proteins, peptides, or other amine-containing molecules. The maleimide group selectively reacts with thiols, allowing conjugation to cysteine residues or thiolated compounds. This makes it valuable in drug delivery systems, where it links therapeutic agents to targeting molecules like antibodies or peptides. It is also utilized in the development of antibody-drug conjugates (ADCs) and PEGylation strategies to enhance the stability, solubility, and circulation time of biologics. Additionally, it plays a role in surface modification of nanoparticles and biomaterials for biomedical applications.