Since binary became a computer language, the development of human society has been greatly accelerated. 0 and 1 have changed the way of human life in countless circuits. The emergence of computers is like a big explosion in the information age, enabling human beings to quickly process a large amount of data. Both daily life and scientific frontier research have undergone earth-shaking changes.
A large amount of data has brought changes and tests. According to statistics, the total global data in 2021 will reach 84.5ZB. (1ZB=1021B) Such a huge amount of data not only puts forward high requirements for computing power, but also puts forward high requirements for storage power. In order to store such a large amount of data, data has also been housed in “buildings” such as data centers. By 2024, the number of super-scale data centers in the world may reach 1000. More and more data centers are built, but the land resources are limited. It is a luxury to build “skyscrapers” in data centers, so improving data storage density becomes another solution.
In order to find a more efficient storage carrier, researchers have focused on the carrier DNA of genetic information in nature. As a term of genetics, DNA is no stranger to the public. In the genetic process, DNA sequence stores genetic information, and then copies genetic information through the process of transcription and translation to maintain biological development and normal operation. Some researchers once suspected that aliens (or advanced civilizations) stored some information in the genome of organisms, waiting for human beings to decrypt it. This seems to be a guess in science fiction, but it is actually based on an important fact: DNA has transmitted important information in human evolution for thousands of years, and is one of the most intensive and stable information media known.
How can DNA storage technology be realized and what changes can it bring?
01
Is DNA storage reliable?
On the technical level, DNA storage has been proved to be feasible.
The idea of using DNA to store information can be traced back to the emergence of molecular biology. Frederick Sanger, a biochemist, invented the Sanger sequencing method to make the DNA sequence measurable. From then on, humans can read the nucleotide sequence, which is arranged and combined with the codes A, T, C and G. Since 0 and 1 can become computer languages, it is also possible to transfer specific information using DNA sequences. However, at that time, it cost 6000 dollars to synthesize a 10-base DNA sequence, although the material performance was good and the price was too high.
With the development of new technology of DNA synthesis and sequencing, DNA as a digital storage medium is no longer a fantasy. In 2001, a research group wrote two famous Dickens sayings into the DNA sequence. Three bases are used to represent an English letter, such as A=AAA, B=AAC. In 2009, a research team successfully coded the lyrics, music scores and a picture of the children’s song “Mary has a little lamb” into a set of DNA sequences.
There are two main advantages of DNA storage. First, the storage conditions are simple. As long as the temperature of DNA is kept low enough, the data can be saved for thousands of years, so the cost of ownership is almost zero; DNA can accurately load massive amounts of data with far higher density than electronic devices. DNA storage technology is more suitable for storing important “cold data” without frequent access and call. “Cold data” can be saved for more than 1000 years in theory under the condition of near zero energy consumption. In the future, DNA storage is likely to become the main storage medium for huge cold data storage.
Second, DNA storage density is large, and the area is small. If it is stored in the form of DNA, every film produced can be stored in a space smaller than sugar. According to the calculation published by George Church of Harvard University and his colleagues on Nature Materials in 2016, the storage density of simple bacterial Escherichia coli is about 1019 bits per cubic centimeter. At this density, a DNA cube with a side length of about one meter can well meet the world’s current storage needs for one year. In terms of weight, the data storage capacity of each gram of DNA can reach 215PB, about 225443840 gigabytes (GB), equivalent to the data storage capacity of 220000 1TB hard disks.
02
Breakthrough in DNA storage
In recent years, some breakthroughs have been made in the research of DNA storage. DNA has been used by researchers to manage data in different ways, and these researchers are trying to understand massive data. The latest advances in next-generation sequencing technology allow the easy simultaneous reading of billions of DNA sequences. With this ability, researchers can use DNA sequences as molecular recognition “tags” to track experimental results.
The research team of Harvard University used CRISPR DNA editing technology to record the image of human hands into the genome of Escherichia coli, and the accuracy of reading exceeded 90%. Swiss researchers have designed a “DNA-of-things” (DoT) storage architecture to produce materials with immutable memory. In the DoT framework, DNA molecules record data, and then these molecules are encapsulated in nano-silica nanoparticles, which are fused into various materials for printing or casting objects of any shape.
Researchers at the University of Washington and Microsoft Research Institute have developed a fully automated system for writing, storing and reading DNA encoded data.
In December 2021, Chinese DNA storage researchers announced the development of a sliding chip – a microfluidic device capable of storing DNA chemicals and various reagents. A slide chip can be an electrode, and its charge will change with the presence/absence of DNA sequence.
In 2022, the synthetic biology team of Tianjin University successfully saved 10 selected Dunhuang murals into DNA, and said that the mural information could be stored for thousands of years at room temperature and 20000 years at 9.4 ℃.
03
DNA storage technology endorsed by giants
Even though DNA storage technology may have cross-era significance, can it really be applied? In this regard, the giants in the storage industry have a positive attitude. Gurtej Sandhu, senior researcher and vice president of Micron Technology, is one of the first members of the project team to participate in the research of DNA storage technology. He participated in the research group of George M. Church of Harvard University in 2016. Seagate has introduced the DNA storage technology of Catalog into its “laboratory on chip”. Seagate’s DNA storage and microfluidic research project has lasted for two and a half years. At present, there are four known patent applications.
The company that cooperates with Seagate is an American start-up company founded in 2016. Catalog once produced DNA fragments of 20-30 base pairs, stitched them up with enzymes, and arranged them in different order to realize data storage. Catalog has used DNA technology to store the novel “Guide to the Galaxy” and the poem “The Way Not Taken”.
Storage giants are optimistic about DNA storage technology, but there are more start-ups with biotechnology as the core on the DNA storage track. The core reason for this phenomenon is that the underlying key technologies of DNA storage technology are actually DNA sequencing technology, DNA synthesis technology and DNA storage technology.
The main companies of DNA data storage technology are also the American start-up Iridia, in addition to the Catalog that cooperates with Seagate. Iridia was founded in 2016 to develop the world’s first commercially attractive DNA-based data storage solution. By combining DNA polymer synthesis technology, electronic nano-switches and semiconductor manufacturing technology, the company is developing a highly parallel format to make the nano-module array have the potential to store data at a very high density.
DNA synthesis technology companies include French company DNA Script and American company Molecular Assemblies.
DNA Script was founded in 2014. The company focuses on using proprietary template-free technology to manufacture synthetic DNA. Through rapid, economical and high-quality DNA synthesis technology, the development of new applications such as new therapies, sustainable chemical production, improved crops and data storage will be greatly accelerated. The company’s unique enzymatic technology and nucleotide chemical synthesis platform can synthesize higher purity and longer DNA sequences, which can improve the accuracy of the sequence by 500 times, speed up the synthesis and shorten the time by 50 times.
Molecular Assemblies was founded in 2013. The enzymatic DNA synthesis technology developed by the company can provide power for new products in the fields of industrial synthetic biology, personalized treatment, accurate diagnosis, information storage, nanotechnology and other fields. The company’s proprietary DNA synthesis method aims to provide cost-effective, reliable and sustainable production of high-quality, sequence-specific DNA.
Founded in 2013, Twist Bioscience is committed to providing high-throughput DNA synthesis and sequencing services to customers in the fields of medical, agricultural, industrial chemicals and data storage. Based on the semiconductor synthetic DNA manufacturing process developed by the company, the reaction volume is reduced by 1 million times, and the output is increased by 1000 times, so as to synthesize 9600 genes on a single silicon chip. In 2016, Microsoft signed an agreement with Twist Bioscience to order about 10 million DNA products for testing DNA data storage capacity.
DNA sequencing companies mainly include Oxford Nanopore Technology, a British company. Oxford Nanopore Technologies was founded in 2005 to develop a subversive electronic single-molecule sensing system based on nanopore science. Oxford Nanopore Technologies has developed a new generation of sensing technology, which uses nanopore – nanopore – embedded in high-tech electronic devices to conduct comprehensive molecular analysis.
In China, in 2019, Huawei announced the establishment of the Strategic Research Institute, which said that it would mainly research and develop cutting-edge technologies, including DNA storage. At the Huawei Global Analyst Conference in 2021, Xu Wenwei, Huawei’s director and president of the Institute of Strategic Studies, said that he would use DNA storage to break through the huge storage space model and coding technology and break the capacity wall.
On May 26, 2021, Sino-Tech Carbon (Shenzhen) Biotechnology Co., Ltd. (C-ATOM) was officially established. In September this year, relying on the early accumulation in the field of DNA storage by Dai Junbiao, a researcher team from the Chinese Academy of Sciences Shenzhen Advanced Technology Research Institute, Kecarbonyuan successfully completed the complete process of DNA storage technology path from coding, synthesis, preservation, sequencing to decoding by independently developing and owning the DNA online encoding and decoding system (“ATOM” for short) with independent intellectual property rights and using the independently imported synthesizer and sequencer.
04
Challenges and potential of DNA storage
At present, there are still some technical problems in the implementation of DNA storage technology. Fan Chunhai, an academician of the CAS Member, said that in the process of DNA storage synthesis, the efficiency of data input and reading is still not high, which takes a long time and costs a lot. Yuan Yingjin, academician of the CAS Member and vice president of Tianjin University, said that DNA information storage is an emerging research direction with deep interdisciplinary integration. If we want to commercialize DNA storage technology, we need research teams from multiple fields to jointly tackle key problems.
If only cost is the problem, then this can be solved eventually. There is no doubt that DNA storage is one of the most potential data storage methods.