Monday, April 09, 2007

DNA Factories

Cheaply churning out made-to-order DNA could revolutionize molecular biology.

By Emily Singer

Credit: Technology Review

Installing one of those prefab, snap-together wood-flooring kits is a lot easier than shaping and sanding rough planks. Adapting a similar construction strategy, a biotech startup called Codon Devices, based in Cambridge, MA, aims to streamline genetic engineering. It makes made-to-order DNA strands, freeing scientists from the finicky work it takes to put together a complicated piece of DNA the old-fashioned way.

That capability could soon change the face of molecular biology. As it becomes cheaper and cheaper to create large chunks of genetic material from scratch, scientists will be able to make ever more complex biological creations. "In the next few years, we'll probably see people engineering cells to do drug delivery or creating cellular sensors," says George Church, a professor of genetics at Harvard and one of Codon's founders. "Maybe even cells that make inorganic objects of interest, like nanostructures."

Codon was founded in 2005 just as the fledgling field of synthetic biology--the quest to design and build new life forms that can perform useful functions--was beginning to take off. The ability to make complex genetic constructs is a cornerstone of the field, allowing scientists to use chunks of DNA to design novel biological parts, which can then be inserted into bacteria or other cells. (See "Synthetic Biology on Display.")

While DNA synthesis is still too expensive to replace more-traditional molecular-biology methods on a broad scale, experts say that the DNA-synthesis market is about to boom, much as the DNA-sequencing market has in the past few years. As sequencing costs plummeted, the number of sequencing projects surged, with record numbers of genomes--even entire microbial communities--being sequenced. "As large companies begin to adopt this technology, the volumes of DNA synthesis will explode," says John Danner, president and chief executive officer of Codon. "When that happens, thousands of scientists will think about this when they go to sleep at night, and that will change how biotech is done."

Last summer, the company created what it believes was the biggest piece of man-made DNA, a 35,000 base-pair strand incorporating several genes needed to synthesize a pharmaceutical compound. The DNA was made for Microbia, another Cambridge-based biotech, which is creating microbes to manufacture specialty chemicals. But the potential applications are broad, spanning pharmaceuticals, energy, and agriculture.

Synthetic biologists are excited about the prospects, but they're still waiting for a decrease in price to the point that they can afford to do the experiments they want to do. "Cost is the critical component to making this technology work," says Chris Voigt, a synthetic biologist at the University of San Francisco. "Right now, we can design one construct that costs a fortune to make. But we want to be able to order different components put together in different ways so we can study the critical factor in putting them together."