A Biological DNA Circuit

A biological cell's DNA can recall its primordial history: The biologists and engineers at MIT design new synthetic biology circuits that combine memory and logic. The biological chip allows scientists to program cells to perform some novel functions such as fluorescing in response to a particular chemical or producing drugs in response to disease markers.



Very soon this new development will prompt the technical revolution from Digital computers to analog computers, a cell circuit can able to translates electrical instructions that naturally written in the cell's genes into a language more intelligible to humans by that human beings and machines "computers" will communicating to each others. The breakthrough in science and biology could help pave the way to highly efficient, highly accurate analog simulations of entire organs. In recent years, analog computers have proven to be much more efficient at simulating biological systems than digital computers.

Timothy Lu is  Associate Professor of Biological Engineering and Electrical Engineering and Computer Science. He is also the senior author of the new study, which appears in the 22 July issue of Science.  In 2013, Lu and other colleagues designed cell circuits that could perform a logic function and then store a memory of the event by encoding it within the cell's DNA. The  machine circuits that they designed  rely on enzymes called recombinases. When activated by a specific input in the cell, such as a chemical signal, recombinases either delete or invert a particular stretch of DNA, depending on the orientation of two DNA target sequences known as recognition sites. The stretch of DNA between those sites may contain recognition sites for other recombinases that respond to different inputs. Flipping or deleting those sites alters what will happen to the DNA if a second or third recombinase is later activated. Therefore, a cell's history can be determined by sequencing its DNA.

Biological circuits:

 Using this special language, the researchers already programmed 60 circuits on span with different functions, and 45 of them worked correctly the first time they were tested. Many of the biological circuits were designed to measure some environmental conditions, such as oxygen level or glucose concentration, and they all respond accordingly. Another circuit was designed to rank three different inputs and then respond based on the priority of each one. Another advantage of this technique is its speed,“It would take years to build these types of circuits" said Voigt.

This blog news presented and written by E.A. Nambili Samuel whom also is a Bio-medical Engineering student at Cyprus International University,Turkey.