HA-100 hydrochloride is a cell-permeable compound known primarily as a protein kinase inhibitor. It is widely used in biochemical and cellular research to study signal transduction pathways. The compound inhibits several key enzymes, including protein kinase A (PKA), protein kinase G (PKG), and protein kinase C (PKC), making it a valuable tool for investigating the roles of these kinases in cellular processes such as proliferation, differentiation, and apoptosis. Researchers apply HA-100 hydrochloride in studies related to cancer biology, where modulation of kinase activity can influence tumor cell growth and survival. It is also used in neuroscience research to examine kinase-dependent mechanisms in neuronal signaling and synaptic plasticity. Due to its broad-spectrum inhibition, it serves as a control agent in experiments requiring suppression of multiple kinase activities simultaneously. Its ability to cross cell membranes enhances its utility in cell-based assays, allowing for effective intracellular delivery without the need for specialized transfection methods. HA-100 hydrochloride is typically employed in vitro, and its use is mainly restricted to experimental settings for mechanistic studies rather than therapeutic applications.