Used as a potent and selective inhibitor of poly(ADP-ribose) polymerase-1 (PARP-1), 5-AIQ hydrochloride is widely applied in research settings to study DNA repair mechanisms, particularly the base excision repair pathway. It helps scientists investigate the role of PARP-1 in cellular responses to DNA damage, making it a valuable tool in cancer research, especially in understanding the sensitization of tumor cells to chemotherapy and radiation. Due to its ability to cross cell membranes effectively, it is employed in in vitro models to modulate PARP activity and assess downstream effects on cell survival, apoptosis, and genomic stability. Its selectivity allows for targeted experiments without significant off-target inhibition, supporting its use in pharmacological studies aimed at developing new therapeutic strategies.