26 Jul

Making DNA Add

Content-Type: text/plain Mime-Version: 1.0 (NeXT Mail 3.3 v118.2) From: Peter Langston <psl> Date: Fri, 26 Jul 96 22:23:45 -0700 To: Fun_People Subject: Making DNA Add Forwarded-by: Keith Bostic <bostic@bsdi.com> Forwarded-by: "Daniel V. Klein" <dvk@lonewolf.com> "Making DNA Add", Frank Guarnieri, Makikio Fliss, Carter Bancroft Science, Vol 273, 12 July 1996, pp 220-223 Abstract: "Recent studies have demonstrated the feasability of using DNA-based experiments to compute solutions to combinatorial problems. However, a prerequisite for designing a computer useful in a wide rane of applications is the ability to perform mathematical calculations. The development of a DNA-based algorithm for addition is presented. The DNA representation of two nonnegative binary numbers is presented in a form permitting a chain of primer extension reactions to carry out the addition operation. To demonstrate the feasibility of this algorithm, a simple example was executed biochemically." The remainder of the paper details the algorithm and results, and goes on to say that "The first generation algorithm described here has an obvious limitation. Because the output is encoded in a different form from the input, it is not presently possible to perform either iterative or parallel addition. The development of a more mature DNA-based algorithm will require modification of the present procedure to take full advantage of the enormous potential of DNA to engage in massively parallel reactions." And further "the algorith describe here is not technically demanding, because the simple biochemical procedures involved require approximately 1 or 2 days of laboratory work." So, while the integer calculations are still measurable in IMPS (that's Instructions per Million Seconds, 5-10 IMPS in this case), I am nonetheless reminded by the 3-page foldout illustration (p65) of a parallel multiplier from "Automatic Digital Computers" by Maurice Wilkes (John Wiley & Sons, 1956), where certain technical problems in programming are noted, or where a description of a magnetic drum made by Ferranti Ltd is described (p181), where it is claimed to hold 128 words of 20 binary digits on each of 256 tracks, the bit density being 98 bpi. Given another 40 years or so, we may have real biochemical computers...

© 1996 Peter Langston