In recent decades, some researchers have been putting the letters of the genetic code to a different use: making tiny nanoscale computers. In a new study, a Duke University team led by professor John Reif created strands of synthetic DNA that, when mixed together in a test tube in the right concentrations, form an analog circuit that can add, subtract and multiply as they form and break bonds. Rather than voltage, DNA circuits use the concentrations of specific DNA strands as signals. Other teams have designed DNA-based circuits that can solve problems ranging from calculating square roots to playing tic-tac-toe. But most DNA circuits are digital, where information is encoded as a sequence of zeroes and ones. Instead, the new Duke device performs calculations in an analog fashion by measuring the varying concentrations of specific DNA molecules directly, without requiring special circuitry to convert them to zeroes and ones first. However, unlike the silicon-based circuits used in most modern day electronics, commercial applications of DNA circuits are still a long way off. http://sciencebulletin.org/archives/4574.html Paper: http://pubs.acs.org/doi/abs/10.1021/acssynbio.6b00144
