SAN DIEGO -- For the next generation of optical storage technology, scientists at the University of California are looking to the sea. A report published in Nature describes newly discovered properties of the green fluorescent protein that gives jellyfish their eerie glow, and explains how those properties could someday be exploited to store and access computer memories in packages the size of a single molecule. Although researchers just discovered the unique switching properties of mutated molecules of the protein procured from the Aequorea victoria jellyfish, they envision a day when computers will use the genes to store optical data, similar to the way bits are stored in values of 1 and 0 now, only in a much smaller space. "This is radically different, since current technology is in no way biologically based," said W.E. Moerner, professor of chemistry and biochemistry at the university. "A single molecule is much smaller than [data storage in] current technology. It could mean creating an extremely small storage element." Green fluorescent proteins are traditionally used as biological markers. Molecular biologists link the mutated genes to proteins in living cells and tissues in order to track those genes. According to the Nature report, this latest discovery represents the first example of a room-temperature optical switch of a mutated jellyfish protein in which each molecule is individually addressable, nondestructively performing readout by way of fluorescence. While studying artificially mutated jellyfish proteins in the single-molecule state, scientist Robert M. Dickson noticed that an emissive molecule excited by a green argon-ion laser at 448 nm emitted a bright yellow color, then blinked to a dark state, not the expected bleached state in which it could no longer absorb light. The team then determined that when the dark molecule absorbed a 405-nm blue light beam from a mercury lamp, it would return to its original emissive state. Team researchers Roger Y. Tsien and Andrew B. Cubitt developed a way to engineer the jellyfish protein to harness the yellow glow for optical storage devices and other potential applications. But for now, the use of mutated jellyfish protein for optical data storage is little more than an intriguing idea. Further engineering to remove the blinking and improve the ability to irradiate one molecule at a time are some of the hurdles scientists face.