Used extensively in bioconjugation processes, this chemical serves as a crosslinking agent to connect proteins, peptides, and other biomolecules. Its maleimide group reacts specifically with thiol groups (-SH) in cysteine residues, while the NHS ester group targets primary amines (-NH2) in lysine residues or N-termini. This dual reactivity makes it highly effective for creating stable covalent bonds between biomolecules, particularly in antibody-drug conjugates (ADCs), protein labeling, and immobilization on surfaces. It is also employed in the development of diagnostic assays and therapeutic agents, where precise and stable molecular linkages are crucial.