Last year, Fred Levine of the University of California in San Diego reported that he had revived dried human cells after 5 days (New Scientist, 19 February 2000, p 11). But this technique doesn't work for normal cells-Levine's team had to genetically modify the cells to make a sugar called trehalose, which protects cells against freezing and drying from the inside.
Other researchers have failed to repeat Levine's results. But he insists the technique works. "We have been drying cells, putting them in a standard cardboard container, sending them [from California] to the East Coast and having them successfully rehydrated," he says. Potts and Helm hope that one day tissues and perhaps even organs could be dried out and revived. But this won't be achieved with glycan alone, Potts says. "In the end it's bound to require a combination of different approaches."