You have to wonder what's going on in the DNA of Harvard genetics professor George Church. About 30 years ago, Prof Church was one of a handful of people who dreamed up the idea of sequencing the entire human genome - every letter in the code that separates us from fruit flies as well as our parents. His lab was the first to come up with a machine to break that code, and he's been working to improve it ever since.

Genes: read, write, edit. To Prof Church, routine whole-genome sequencing will herald the beginning of a new era as transformative and full of possibilities as the Internet Age. But this is not just about insurance companies wanting to have every customer's entire genome in their files.

He envisions a day when a device implanted in your body will be able to identify the first mutations of a potential tumor, or the genes of an invading bacteria. You'll be able to pop an antibiotic targeted at the invader, or a cancer pill aimed at those few renegade cells. Another device will monitor your outside environment, warning you away from sites that pose a health risk. A range of genetic disorders will be identified at birth, or even conception, and tiny, preprogrammed viruses will be sent into the body to penetrate compromised cells and correct the damage. Changing the adult body at the first signs of illness will be just as easy, he predicts.

There's no reason, Prof Church says, why people won't be able to live to be 120, and then 150.

As he pushes for the mapping of more and more complete genomes, he also pushes to make those genomes public, so researchers can learn about medical conditions by comparing them. He's put 11 up on the web already, including his own, and is aiming for 100,000 more.

Once thousands of people with diverse backgrounds have made their genomes and health status public, researchers will be able to delve into a wide range of diseases and disorders, from schizophrenia to heart disease, diabetes to learning disabilities, looking for patterns.

"I think we as a community have a need and a role and responsibility to educate the public as well as to take precautionary safeguards to make sure we're not introducing something that's problematic," says James Collins, who builds his cells with programmable kill switches, so they self-destruct before reproducing or mutating.