HA-100 hydrochloride is primarily used in biochemical research as a potent and selective inhibitor of protein kinases. It is particularly effective in studying cellular signaling pathways, as it inhibits cyclic AMP-dependent protein kinase (PKA) and protein kinase C (PKC). Researchers utilize it to investigate the roles of these kinases in various physiological processes, including cell proliferation, differentiation, and apoptosis. Additionally, it serves as a valuable tool in understanding the mechanisms of diseases where kinase activity is dysregulated, such as cancer and inflammatory disorders. Its application extends to pharmacological studies aimed at developing targeted therapies for kinase-related conditions.