Phenylmethanesulfonyl fluoride is widely used as a serine protease inhibitor in biochemical research. It is commonly applied to prevent protein degradation during cell lysis and protein extraction processes, ensuring the integrity of proteins for analysis. This compound is particularly effective in inhibiting enzymes like trypsin, chymotrypsin, and thrombin, making it valuable in studies involving enzyme kinetics and protein function. Additionally, it is utilized in the preparation of samples for electrophoresis and chromatography to maintain protein stability. Its ability to irreversibly inhibit serine proteases also makes it a useful tool in investigating protease-related pathways and mechanisms in cellular and molecular biology.