New generation DNA storage
The genetic code is millions of times more efficient for data storage than existing solutions, which are expensive, energy-intensive and require a lot of space. At the same time, all digital data on the planet can fit in several tens of kilograms of DNA.
The use of DNA as a high-density data carrier could lead to breakthroughs in biosensor technology and bioregistration and storage of new-generation digital data. However, the composite architecture of modern DNA-based recording methods makes them inherently slow and unable to register fluctuations in signals with sub-hourly frequencies.
In a new study, a group from Northwestern University has proposed a method of recording information in DNA, which takes minutes to complete, not hours or days. The authors used a new enzymatic system for DNA synthesis, which records rapidly reproducing signals from the environment directly into the DNA sequence. This method, if successful, could change the approach by which scientists study and record the activity of brain neurons.
Creating DNA from scratch ex vivo (outside the body) involves a very slow chemical synthesis, which does not allow scaling the method for wide application. The new development for recording information is much cheaper and faster, because it allows you to directly manipulate the enzyme that synthesizes DNA. Unlike existing intracellular recording methods, which are even slower because they require mechanical steps of protein expression in response to signals, the new method allows the necessary enzymes to be expressed in advance.
Bypassing protein expression
Existing methods of intracellular recording of molecular and digital data in DNA are based on composite processes in which new data is added to existing DNA sequences. To perform an accurate recording, researchers must stimulate and suppress the expression of specific proteins, which can take more than 10 hours.
The authors suggested that synthesizing a completely new DNA instead of copying its template would make the recording process faster and with higher resolution. They developed a simplified system using a single enzyme – terminal deoxynucleotidyltransferase (TdT) – to transmit environmental signals to DNA. TdT adds nucleotides to the ends of single-stranded DNA in a template-independent manner, choosing bases according to environmental conditions. This time-sensitive unconventional recording method using TdT for local Environmental Signals (Time-sensitive Untemplated Recording using Tdt for Local Environmental Signals, TURTLES) recorded data into the genetic code within minutes, not hours. Environmental changes include an increase in the levels of metals or other molecules, they are fixed by TdT. The resulting synthetic DNA is a molecular running line that tells scientists the time and nature of changes in the environment.
Using TURTLES inside cells will give researchers the opportunity to use recorded DNA to learn, for example, about how brain cells interact with each other in order to study in detail currently unavailable mechanisms.
Outside the body, the TURTLES system can be used for various solutions aimed at meeting the growing need for data storage (up to 175 zettabytes by 2025).
This is especially important for applications with archived data, such as, for example, CCTV footage, which must be stored for a long time and be available in case of an incident. With the help of technology developed by engineers, hard drives and floppy drives on which years of memory are recorded can also be replaced with fragments of synthetic DNA. In addition, the TURTLES technology can be used to monitor the levels of pollutants in the environment.
The genomic infrastructure and cellular methods necessary for reliable intracellular recording are still being finalized, and this study is another step towards achieving a long–term goal.
Article N.Bhan et al. Recording Temporal Signals with Minutes Resolution Using Enzymatic DNA Synthesis is published in the Journal of the American Chemical Society.
Aminat Adzhieva, portal "Eternal Youth" http://vechnayamolodost.ru based on the materials of Northwestern University: Our DNA is becoming the world's tiniest hard drive.