Building Artificial Viruses

In the past five years, new technology has made it easier to genetically modify microbes and even create new ones from scratch. Some worry that the developments could lead to novel and more dangerous kinds of bioterror threats.

Using a kind of chemical epoxy, the scientist and his crew of graduate assistants begin the tedious task of fusing small snippets of DNA into larger fragments. Then they splice together the larger strands until the entire sequence is complete.

The final step is almost magical. The finished but lifeless DNA, placed in a broth of organic "juice" from mushed-up cells, begins making proteins. Spontaneously, it assembles the trappings of a working virus around itself.

While simple on paper, it is not a feat for amateurs, Wimmer said. There are additional steps to making effective bioweapons besides acquiring microbes. Like many scientists and a sizable number of biodefense experts, Wimmer believes traditional terrorist groups such as al-Qaeda will stick with easier methods, at least for now.

Yet al-Qaeda is known to have sought bioweapons and has recruited experts, including microbiologists. And for any skilled microbiologist trained in modern techniques, Wimmer acknowledged, synthetic viruses are well within reach and getting easier.

"This," he said, "is a wake-up call."

From Parlor Trick to Bio-Bricks

The global biotech revolution underway is more than mere genetic engineering. It is genetic engineering on hyperdrive. New scientific disciplines such as synthetic biology, practiced not only in the United States but also in new white-coat enclaves in China and Cuba, seek not to tweak biological systems but to reinvent them.

The holy grail of synthetic biologists is the reduction of all life processes into building blocks -- interchangeable bio-bricks that can be reassembled into new forms. The technology envisions new species of microbes built from the bottom up: "living machines from off-the-shelf chemicals" to suit the needs of science, said Jonathan Tucker, a bioweapons expert with the Washington-based Center for Non-Proliferation Studies.

"It is possible to engineer living organisms the way people now engineer electronic circuits," Tucker said. In the future, he said, these microbes could produce cheap drugs, detect toxic chemicals, break down pollutants, repair defective genes, destroy cancer cells and generate hydrogen for fuel.

In less than five years, synthetic biology has gone from a kind of scientific parlor trick, useful for such things as creating glow-in-the-dark fish, to a cutting-edge bioscience with enormous commercial potential, said Eileen Choffnes, an expert on microbial threats with the National Academies' Institute of Medicine. "Now the technology can be even done at the lab bench in high school," she said.

Along with synthetic biologists, a separate but equally ardent group is pursuing DNA shuffling, a kind of directed evolution that imbues microbes with new traits. Another faction seeks novel ways to deliver chemicals and medicines, using ultra-fine aerosols that penetrate deeply into the lungs or new forms of microencapsulated packaging that control how drugs are released in the body.

Still another group is discovering ways to manipulate the essential biological circuitry of humans, using chemicals or engineered microbes to shut down defective genes or regulate the production of hormones controlling such functions as metabolism and mood.

Some analysts have compared the flowering of biotechnology to the start of the nuclear age in the past century, but there are important differences. This time, the United States holds no monopoly over the emerging science, as it did in the early years of nuclear power. Racing to exploit each new discovery are dozens of countries, many of them in the developing world.