Created by computer based on DNA, which finally can be reprogrammed
It is believed that the DNA will save us from computers. Thanks to advances in replacing silicon transistors, computers based on the DNA promise to provide us with the massive parallel computing architecture, are impossible now. But here's the rub: the molecular circuits that have been created up to now, did not have absolutely no flexibility. Today the use of DNA for computation - it's the same thing as "to create a new computer from new equipment to run only one program," said scientist David Doty.
Doty, a professor of the University of California at Davis, and colleagues decided to find out what is required to create a DNA computer, which can actually be reprogrammed.
DNA of the computer
In an article published this week in the journal Nature, Doty and his colleagues at the University of California and the University of Maynooth demonstrated just that. They showed that it is possible to use a simple trigger to make the same base set of DNA molecules to implement a number of different algorithms. Although this research is still exploratory in nature, in the future it may be used reprogrammable molecular algorithms to program DNA robots that have already successfully delivered drugs to cancer cells.
"This is one of the most important works in the field," says Lars-Thorsten Schmidt, associate professor of the Department of Experimental Biophysics at Kent State University who was not involved in the study. "Previously algorithmic self-assembly, but not to the degree of difficulty."
In electronic computers like the fact that you are using to read this article - bits are binary bits of information that tell the computer what to do. They represent discrete physical condition of the underlying hardware, typically in the form of the presence or absence of an electric current. These bits - or even the electrical signals that implement them - are transmitted through circuit consisting of logic elements which perform the operation with one or more input bits and output one bit as the output.
Combining these simple building blocks again and again, the computers can run surprisingly sophisticated programs. The idea behind DNA computing, is to replace the chemical bonds electrical signals and nucleic acids - silicon, and create biomolecular software. According to Erik Winfree, a computer scientist from Caltech and co-operation, molecular algorithms use a natural ability to process information sewn into the DNA, but instead of giving control nature, "the growth process control computers."
Over the past 20 years in several experiments, molecular algorithms for things like tic-tac-toe or assembly of different pieces. In each of these cases, the DNA sequence had to be carefully designed to create a specific algorithm to generate the structure of DNA. What is different in this case is the fact that researchers have developed a system in which the same basic DNA fragments can be ordered to create an entirely different algorithms and thus made different end products. This process begins with DNA origami method of folding a long section of DNA into the desired shape. This piece of DNA serves as a folded "Sid" (seed, seed), which triggers an algorithmic conveyor, just as a thread, in a lowered podsaharennyh water gradually grows caramel. Seed remains largely the same regardless of the algorithm, and changes are made only to several smaller sequences for each new experiment.
Once researchers have created seed are added as a solution of 100 other DNA strands, the DNA fragments. These fragments, each of which consists of the unique location 42 nucleobases (four major biological compounds that comprise DNA) are taken from a large collection of DNA fragments 355 creates scientists. To create a different algorithm, scientists need to select a different set of starting fragments. Molecular algorithm includes random walk, requires different sets of DNA fragments which utilizes an algorithm to calculate. Since these DNA fragments were joined during assembly, they form a circuit which implements the selected molecular algorithm on the input bits provided to LED.
Using this system, scientists have created 21 different algorithms that can perform tasks such as recognizing multiples of three, leadership selection, generation patterns and the score to 63. All of these algorithms have been implemented using various combinations of the same 355 DNA fragments. Of course, to write the code by dropping DNA fragments into the tube until you get it, but this whole thing is a model for future iterations of flexible computer-based DNA. If Doty, Winfrey and Woods have their way, molecular programmers of tomorrow even think about will not biomechanics underlying their programs in the same way as modern programmers do not have to understand the physics of transistors to write good software.
The potential uses of this technology nanoscale assembly of the imagination, but these forecasts are based on our relatively limited understanding of the nanoscale world. Alan Turing was unable to predict the emergence of the Internet, so we may expect the application of molecular informatics incomprehensible.
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