m-PEG12-NHS ester is widely used in bioconjugation and modification of biomolecules. It is particularly valuable in attaching polyethylene glycol (PEG) chains to proteins, peptides, or other molecules to improve their solubility, stability, and circulation time in biological systems. This chemical is commonly applied in drug delivery systems to enhance the pharmacokinetic properties of therapeutic agents, reducing immunogenicity and prolonging their half-life in the body. It is also utilized in the development of PEGylated biopharmaceuticals, such as antibodies and enzymes, to optimize their therapeutic efficacy. Additionally, m-PEG12-NHS ester finds applications in surface modification of nanoparticles and biomaterials, enabling better biocompatibility and targeted delivery in biomedical research.