In order to record the entire content of the Internet in DNA code format, it would take only a couple of kilograms of this substance, assuming that 1 gram of DNA can hold 215 petabytes information. However, scientists from the University of Illinois at Urbana-Champaign thought this was not enough, so they increased the capacity of DNA by adding new elements of the genetic “alphabet” to it. They added seven more to the four basic “letters” and managed to double the memory capacity of DNA.
DNA formed in the course of evolution to transmit information only about the structure of a living being, therefore, it is poorly suited as a universal data storage device. Scientists have developed special chemically modified nucleotides that can be inserted into the code without harming the basic structure of DNA – and more importantly, with little or no increase in its volume. That is, in the same physical space it is now possible to store many more combinations of “letters”, which proportionally increases the number of “words”.
The downside of the system is that it ceases to be a purely biological structure, because the standard DNA reading mechanisms no longer work in this case. Scientists had to synthesize a special protein with nanopores through which DNA strands must be pulled. It perfectly recognizes both biological and synthetic letters, and the decoder combines them into words using machine learning methods, recognizing the recorded information.
The transition to bio-cybernetic constructions made it possible not only to increase the capacity of DNA, but also to speed up the recording and reading of data. In nature, this is a rather slow process, but scientists managed to improve its performance by at least twice. And this opens the way to the creation of effective data carriers based on modified DNA.
Source – Nano Letters