2007 Volume 75 Issue 7 Pages 513-517
A 3-channel (3C) microinjector was prepared by pulling a glass capillary. One channel was used for a potential measuring electrode (MeaE) and the other two channels were used for electrophoretic introduction electrode (IntE) and its counter electrode (CE). The 3C microinjector was propelled by an oil pressure manipulator that was driven by a pulse motor, while the MeaE output was recorded continuously. When the 3C microinjector penetrated the cell membrane of a tobacco cultured cell, BY-2, the output potential changed sharply towards the negative direction. Then the microinjector progressed further into the cell. A marked change of the output potential occurred again, though it was towards the positive direction. These changes were speculated as the passages of cell membrane and vacuolar membrane, respectively. Using the differential of these changes as the stop signal, the microinjector could rightly be stopped either in the cytosol or the vacuole, which was confirmed by the dye diffusion pattern.