If it’s not alive, but not dead, what is it?

That’s the riddle posed by the new field of ‘partial life’ technologies, to be explored today in a symposium sponsored by San Francisco’s Exploratorium. An international panel of researchers, artists and entrepreneurs will present provocative — and perhaps useful — new projects that blur the boundaries between the natural and the artificial.

Take, for example, the DNA molecule built in the lab of Stanford University chemistry Professor Eric T. Kool.

It is larger than life, wider than any found in nature. Besides being more heat-resistant than natural DNA, the new version glows in the dark. While it can’t reproduce like natural DNA, it shares some of DNA’s traits.

“We’ve designed a genetic system that’s completely new and unlike any living system on Earth,” said Kool. He calls it “expanded DNA,” or xDNA.

Other innovative projects include: