RH421 is a fast responding membrane potential dye, exhibiting >20% fluorescence change per 100 mV on neuroblastoma cells.    &lamba; Ex/&lamba; Em = 515/704 nm (MeOH)  Red solid soluble in DMSO, EtOH or DMF  Store at -20°C and protect from light, especially in solution  C29H42N2O3S  MW: 498.72  [107610-19-5]