Such interactions between biology and computer science are very valuable for the scientific community in general, Lipton says. Still lacking, however, is a significant body of lab work clearly demonstrating the feasibility of DNA operations on a scale anywhere near that contemplated by the computer scientists. As the biochemists pointed out, getting precisely the results that one wants is no simple matter, and pioneering lab work can require months, if not years, of effort. Computer science graduate students who have ventured into the lab have learned the same lesson. The big underlying question in DNA computing, however, concerns its potential application.
None is clearly so important that it by itself justifies the construction of DNA computers.
In the early days of personal computers, for example, it was the invention of spreadsheet programs that created a real need for PCs. So, we've put a lot of effort into thinking about what we are going to do with this technology, if it works. Current models of DNA computation involve huge numbers of molecules, each one corresponding to a processor in a certain state and operating independently of all the others. In effect, these molecules work simultaneously but individually. It may be desirable, however, to have some way of passing information from one strand to another, establishing communication among the DNA strands.