Death of a Cell

Scientists at the University of Manchester have recorded a cell’s final pulse of electrical activity. As part of an experiment to understand cellular signaling mechanisms, the researchers built an array of charge-sensitive semiconductor electrodes and placed a yeast cell on top of it (left). The researchers detected variations between charge readings from the electrodes, measuring the flow of ions that cells need to stay alive. After dousing the cell with ethanol to make its electrical activity easier to detect, physicist Andre Geim measured ion flow to a resolution of about 10 ions. Sadly, the ethanol killed the cell. The last detectable ion reading “was probably the last gasp,” Geim says.