The existence of strong electric fields across cellular membranes is accepted as a basic fact of cell biology. Maintaining gradients of charged molecules and ions allows for many cellular functions, from control over cell volume to the electrical discharges of nerve and muscle cells.
The fact that cells have internal electric fields, however, is surprising. Kopelman presented his results at the annual meeting of the American Society for Cell Biology this month. “There has been no skepticism as to the measurements,” says Kopelman. “But we don’t have an interpretation.”
Daniel Chu of the University of Washington in Seattle agrees that Kopelman’s work provides proof of concept that cells have internal electric fields. “It’s bound to be important, but nobody has looked at it yet,” Chu says.
Grodzinski says that an interesting application of the voltmeters will be to examine whether there’s a difference in electrical signals between healthy and diseased cells, and whether different disease stages might have characteristic electrical signatures. To gauge the viability of the technique, researchers will need to “start tying it to biology by studying cell lines from the clinic,” says Grodzinski. “This is a first demonstration.”