Mal-amido-PEG12-NHS is widely used in bioconjugation and chemical biology for attaching biomolecules to various substrates. Its PEG spacer provides solubility and reduces steric hindrance, making it ideal for linking proteins, peptides, or antibodies to surfaces, nanoparticles, or other molecules. The NHS ester group reacts efficiently with primary amines, enabling stable amide bond formation. This compound is particularly valuable in drug delivery systems, where it facilitates the targeted attachment of therapeutic agents to carriers. It is also employed in diagnostic assays, where it helps immobilize detection molecules onto solid supports, enhancing sensitivity and specificity. Additionally, it is used in the development of bioconjugates for research purposes, such as studying protein interactions or cellular uptake mechanisms.