Di-4-ANEPPS is a fast-response, electrochromic membrane potential fluorescent probe based on a naphthylstyrylpyridinium structure. Its response mechanism involves membrane potential changes causing intramolecular charge transfer, leading to a blue shift in the excitation spectrum. It enables real-time detection of millisecond-scale transient membrane potential changes in excitable cells (e.g., neurons and cardiomyocytes) through ratiometric imaging. Di-4-ANEPPS is non-fluorescent before incorporating into lipid membranes; after incorporation, excitation/emission peaks are approximately in the 465-482 nm/635-686 nm range. Besides being widely used in cardiac electrophysiology and drug cardiac toxicity assessment, it is also a target molecule in studies of singlet oxygen-mediated photooxidative damage at membrane interfaces. Note that Di-4-ANEPPS itself may cause non-reversible interference with cardiac conduction parameters (e.g., heart rate, conduction velocity) at high concentrations or under prolonged illumination and can inhibit sodium current.

DMSO: 10 mg/mL (20.8 mM), Sonication is recommended.