N-(2-Aminoethyl)maleimide Hydrochloride is widely used in biochemical research, particularly in protein labeling and conjugation studies. Its maleimide group reacts specifically with thiol groups in cysteine residues, making it valuable for attaching fluorescent dyes, biotin, or other functional groups to proteins or peptides. This property is essential for studying protein interactions, cellular localization, and dynamics. Additionally, it is employed in the preparation of antibody-drug conjugates (ADCs) for targeted cancer therapies, where it helps link cytotoxic drugs to antibodies. Its stability and reactivity under physiological conditions make it a preferred choice for creating stable covalent bonds in bioconjugation applications.