Leupeptin hydrochloride is widely used in biochemical research as a protease inhibitor. It effectively inhibits serine, cysteine, and threonine proteases, making it valuable in studying protein degradation and enzyme mechanisms. In cell culture studies, it helps prevent protein breakdown, ensuring the integrity of proteins during experimental procedures. It is also utilized in the investigation of apoptosis and autophagy pathways, providing insights into cellular processes. Additionally, leupeptin hydrochloride is employed in the preparation of cell lysates to preserve protein stability for further analysis. Its role in inhibiting proteases makes it a crucial tool in understanding disease mechanisms and developing therapeutic strategies.