Widely used as an irreversible serine protease inhibitor in biochemical and molecular biology research. It effectively inactivates enzymes such as trypsin, chymotrypsin, and thrombin by covalently modifying the active site serine residue. Commonly added to protein extraction buffers to prevent proteolysis during cell lysis and protein purification. Particularly useful in studies involving membrane proteins and receptor complexes where broad-spectrum protease inhibition is required. Also employed in activity-based protein profiling to identify active enzymes in complex mixtures. Its relative stability in aqueous solution and specificity make it a preferred choice over more labile inhibitors like PMSF in certain experimental conditions.