Apoptotic rate of MAGIC-5 cells in response to electrical stimulation. MAGIC-5 cells were cultured for 3 h at 37°C on PLL-coated ITO electrodes and then stimulated by a d.c. potential of 1.0 V (vs. Ag/AgCl) for 3 to 15 min. Apoptotic cells were measured using an Apoptosis In Situ Detection Kit. More than 1,000 cells were counted under a microscope. Data represent the geometric means of duplicate determinations.