Leupeptin hemisulfate salt is widely used in biochemical and cell biology research as a protease inhibitor. It effectively inhibits serine and cysteine proteases, making it valuable for preventing protein degradation during cell lysis and protein extraction processes. This property ensures the integrity of proteins for downstream applications such as Western blotting, enzyme assays, and protein purification. Additionally, it is employed in studies involving apoptosis and autophagy to regulate protease activity and investigate cellular mechanisms. Its ability to stabilize proteins and peptides also makes it useful in structural biology and drug discovery research.