DNA computing

DNA computing is a branch of computing which uses DNA, biochemistry, and molecular biology hardware, instead of the traditional silicon-based computer technologies. Research and development in this area concerns theory, experiments, and applications of DNA computing. The term 'molectronics' has sometimes been used, but this term has already been used for an earlier technology, a then-unsuccessful rival of the first integrated circuits; this term has also been used more generally, for molecular-scale electronic technology. DNA computing is a branch of computing which uses DNA, biochemistry, and molecular biology hardware, instead of the traditional silicon-based computer technologies. Research and development in this area concerns theory, experiments, and applications of DNA computing. The term 'molectronics' has sometimes been used, but this term has already been used for an earlier technology, a then-unsuccessful rival of the first integrated circuits; this term has also been used more generally, for molecular-scale electronic technology. This field was initially developed by Leonard Adleman of the University of Southern California, in 1994. Adleman demonstrated a proof-of-concept use of DNA as a form of computation which solved the seven-point Hamiltonian path problem. Since the initial Adleman experiments, advances have been made and various Turing machines have been proven to be constructible. While the initial interest was in using this novel approach to tackle NP-hard problems, it was soon realized that they may not be best suited for this type of computation, and several proposals have been made to find a 'killer application' for this approach. In 1997, computer scientist Mitsunori Ogihara working with biologist Animesh Ray suggested one to be the evaluation of Boolean circuits and described an implementation. In 2002, researchers from the Weizmann Institute of Science in Rehovot, Israel, unveiled a programmable molecular computing machine composed of enzymes and DNA molecules instead of silicon microchips. On April 28, 2004, Ehud Shapiro, Yaakov Benenson, Binyamin Gil, Uri Ben-Dor, and Rivka Adar at the Weizmann Institute announced in the journal Nature that they had constructed a DNA computer coupled with an input and output module which would theoretically be capable of diagnosing cancerous activity within a cell, and releasing an anti-cancer drug upon diagnosis. In January 2013, researchers were able to store a JPEG photograph, a set of Shakespearean sonnets, and an audio file of Martin Luther King, Jr.'s speech I Have a Dream on DNA digital data storage. In March 2013, researchers created a transcriptor (a biological transistor). In August 2016, researchers used the CRISPR gene-editing system to insert a GIF of a galloping horse and rider into the DNA of living bacteria. Latest research on DNA computing can perform reversible DNA computing bringing it one step closer to the silicon-based computing used in PC. In particular, John Reif and his group at Duke University proposed two different techniques to reuse the computing DNA complexes. The first design uses dsDNA gates while the second design uses DNA hairpin complexes. While both the designs face some issues such as reaction leaks, this is a significant breakthrough in the field of DNA computing. The organisation and complexity of all living beings is based on a coding system functioning with four key components of the DNA-molecule. Because of this, the DNA is very suited as a medium for data processing. According to different calculations a DNA-computer with one liter of fluid containing six grams of DNA could potentially have a memory capacity of 3072 exabytes. The theoretical maximum data transfer speed would also be enormous due to the massive parallelism of the calculations. Therefore, about 1000 petaFLOPS could be reached, while today's most powerful computers do not go above a few dozen (99 petaFLOPS being the current record).