The potential for danger in this new technology really depends on how effective the emerging techniques will be in actually creating viable biomachines like artificial viruses. Conference attendees seemed to assume that the field will proceed along the same time line as the semiconductor industry. The current state of the art for synthetic biology corresponds to the first steps engineers took to put a few gates on a chip, thus kicking off the chip revolution.
One factor that could speed up the process is the experience that has been gained with electronic design systems throughout the 40 years of VLSI advances. Today's digital circuit designers are uniquely positioned to take advantage of the new field's decoupling of design and implementation. An accident of nature makes it possible to describe cellular processes in terms of the familiar AND, OR and NOT logic operations of digital circuits. So if successful, the synthetic biology movement could lower the entry barrier for electrical engineers for a novel nanotechnology arena-one with broad applications in industry and particularly in medicine. Prototype biodesign systems are already emerging.
But the larger unknown is the speed of the implementation phase. First, standard biochemical modules with standard inputs and outputs will have to be defined. Then some automated, highly parallel manufacturing system will have to be designed that can take a description of a system in terms of standard parts and crank out actual biological components.
"My impression is that biology is still in the dignified style of the English countryside," Knight said. "Practitioners go into the lab and if something works, that's great and if it doesn't, they come back the next day and try again. . . . We have an opportunity to take that stately pace and accelerate it a lot," he said. " Some people here have already developed many of the tools to do that. There is a lot of power and danger here, but I would like to think that the advantages that come with the power outweigh the dangers."
Market pressures are already promptting biotech companies to speed up the DNA synthesis process. Another panelist, John Mulligan, a genetic engineer who started Blue Heron Inc. (Bothell, Wash.) based on his own automated DNA synthesis line, discussed some of the basic enabling technologies that are based on microfluidic chips and robotics.
Mulligan pointed out that speed of synthesis does not just involve the problem of how fast a string of amino acids can be assembled. Chemical reactions are prone to errors, and a major barrier that slows down DNA synthesis is the need to correct errors and verify the correctness of a molecule that can have hundreds of millions of base pairs, Mulligan said.
The large pool of expertise that has been gained by the semiconductor industry in its successful bid to crank out chips with hundreds of millions of transistors is of no use to biological synthesis, however. In fact, the self-replicating nature of biological systems is a built-in manufacturing system, although one that is prone to variations in the form of mutations.
The danger in biosynthesized systems stems from the ability of biological processes to easily support self-replication. Some observers believe that self-replication itself should be strictly banned as the only way to fend off the threat of some engineered molecular system running rampant. But such a restriction would take away much of the power of synthetic biology. And with the pace of innovation, it may already be too late to put the self-replicating genie back in the bottle.