A team of scientists at the University of Wisconsin, Madison has shown that DNA computing is possible on a gold-plated chip no bigger than a ticket stub (Nature 403, 175– 179, 2000.) By encoding immobilized DNA strands to represent all possible solutions of a logical problem and serially introducing complements of the strands as probes that meet the criteria of the solution, they were able to create steps equivalent to the Boolean functions “AND” and “OR.” After the probes hybridized on the chip, any single strands (representing “wrong answers”) were destroyed by addition of an enzyme. The remaining DNA was stripped of probe and the cycle repeated until all conditions were fulfilled. By PCR amplifying the remaining DNA and reading it on the fluorescent array, the scientists found the correct solution. “This is the culmination of three subprojects. . .In this paper, we put all the little pieces together and demonstrate a calculation,” says Robert Corn, professor of chemistry at the University of Wisconsin, Madison. Currently, research is underway to reduce binding and reading error, and create an “append” step, which could function as the chemical “IF”. DNA computing has the potential to co-process an almost infinite number of variables simultaneously. Any additional variable in a logic problem thus requires a single additional step rather than increasing calculations exponentially, as in conventional computing.