Cayman’s Autophagy/Cytotoxicity Dual Staining provides a convenient tool for studying the regulation of autophagy and cytotoxicity at the cellular level. The kit employs MDC, an autofluorescent substance incorporated into multilamellar bodies by both an ion trapping mechanism and the interaction with membrane lipids, as a probe for detection of autophagic vacuoles in cultured cells. Propidium iodide is used as a marker of cell death.