Life Science Open Day | 2006 | Weizmann Institute of Science 972 8 934 2125 | 4494 Department of Biological Chemistry 972 8 934 4484 Ehud.Shapiro@weizmann.ac.il, Electronic computers and living organisms are similar in their ability to carry out complex physical processes under the control of digital information - electronic gate switching controlled by computer programs and organism biochemistry controlled by the genome. Yet they are worlds apart in their basic building blocks - wires and logic gates on the one hand, and biological molecules on the other hand. While electronic computers, first realized in the 1940’s are the only “computer species” we are accustomed to, the abstract notion of a universal programmable computer, conceived by Alan Turing in 1936, has nothing to do with wires and logic gates. In fact, Turing’s design of the so-called Turing machine has striking similarities to information-processing biomolecular machines such as the ribosome and polymerases. This similarity holds the promise that biological molecules can be used to create a new “computer species”. Such computers can have direct access to a patient’s biochemistry, a major advantage over electronic computers used for medical applications. Eventually, progress in the development of the molecular computers may lead to a “Doctor in a Cell”: A biomolecular computer that operates inside the living body, programmed with medical knowledge to diagnose diseases and produce Laboratory for Biomolecular Computers Ehud Shapiro Rivka Adar Tuval Ben Yehezkel Binyamin Gil Michal Golan-Mashiach Dan Frumkin Shai Kaplan Gregory Linshiz Adam Wasserstrom Yishai Admanit Maya Kahan Olga Shomron www.wisdom.weizmann.ac.il/~udi Fig. 1 a. The overall process: The gray section is made up of four symbols, each of which checks for a different disease marker. The middle module (purple or beige) verifies the final diagnosis, and facilitates the release of either a drug or drug suppressor (darker colored loop at the end). b. A demonstration of the detection of a present marker (mRNA) that changes transitions concentratins. c. Demonstration of the stochasticity. d. Output operation; the final active drug concentration depends on the ratio between drug and drug-suppressor release.