The Brave New World of Using DNA to Store Data
A panoramic view of DNA
Netscape co-founder-turned-venture capitalist billionaire investor Marc Andreessen once posited that software was eating the world. He was right, and the takeover of software resulted in many things. One of them is data. Lots and lots and lots of data. In the previous two years, humanity created more data than it did during its entire existence combined, and the amount will only increase. Think about it: The hundreds of 50KB emails you write a day, the dozens of 10MB photos, the minute-long, 350MB 4K video you shoot on your iPhone X add up to vast quantities of information. All that information needs to be stored. And that's becoming an issue as data volume outpaces storage space.
The race is on to find another medium capable of storing massive amounts of information in as small a space as possible.
"There won't be enough silicon to store all the data we need. It's unlikely that we can make flash memory smaller. We have reached the physical limits," Victor Zhirnov, chief scientist at the Semiconductor Research Corporation, says. "We are facing a crisis that's comparable to the oil crisis in the 1970s. By 2050, we're going to need to store 10 to the 30 bits, compared to 10 to the 23 bits in 2016." That amount of storage space is equivalent to each of the world's seven billion people owning almost six trillion -- that's 10 to the 12th power -- iPhone Xs with 256GB storage space.
The race is on to find another medium capable of storing massive amounts of information in as small a space as possible. Zhirnov and other scientists are looking at the human body, looking to DNA. "Nature has nailed it," Luis Ceze, a professor in the Department of Computer Science and Engineering at the University of Washington, says. "DNA is a molecular storage medium that is remarkable. It's incredibly dense, many, many thousands of times denser than the densest technology that we have today. And DNA is remarkably general. Any information you can map in bits you can store in DNA." It's so dense -- able to store a theoretical maximum of 215 petabytes (215 million gigabytes) in a single gram -- that all the data ever produced could be stored in the back of a tractor trailer truck.
Writing DNA can be an energy-efficient process, too. Consider how the human body is constantly writing and rewriting DNA, and does so on a couple thousand calories a day. And all it needs for storage is a cool, dark place, a significant energy savings when compared to server farms that require huge amounts of energy to run and even more energy to cool.
Picture it: tiny specks of inert DNA made from silicon or another material, stored in cool, dark, dry areas, preserved for all time.
Researchers first succeeded in encoding data onto DNA in 2012, when Harvard University geneticists George Church and Sri Kosuri wrote a 52,000-word book on A, C, G, and T base pairs. Their method only produced 1.28 petabytes per gram of DNA, however, a volume exceeded the next year when a group encoded all 154 Shakespeare sonnets and a 26-second clip of Martin Luther King's "I Have A Dream" speech. In 2017, Columbia University researchers Yaniv Erlich and Dina Zielinski made the process 60 percent more efficient.
The limiting factor today is cost. Erlich said the work his team did cost $7,000 to encode and decode two megabytes of data. To become useful in a widespread way, the price per megabyte needs to plummet. Even advocates concede this point. "Of course it is expensive," Zhirnov says. "But look how much magnetic storage cost in the 1980s. What you store today in your iPhone for virtually nothing would cost many millions of dollars in 1982." There's reason to think the price will continue to fall. Genome readers are improving, getting cheaper, faster, and smaller, and genome sequencing becomes cheaper every year, too. Picture it: tiny specks of inert DNA made from silicon or another material, stored in cool, dark, dry areas, preserved for all time.
"It just takes a few minutes to double a sample. A few more minutes, you double it again. Very quickly, you have thousands or millions of new copies."
Plus, DNA has another advantage over more traditional forms of storage: It's very easy to reproduce. "If you want a second copy of a hard disk drive, you need components for a disk drive, hook both drives up to a computer, and copy. That's a pain," Nick Goldman, a researcher at the European Bioinformatics Institute, says. "DNA, once you have that first sample, it's a process that is absolutely routine in thousands of laboratories around the world to multiply that using polymerase chain reaction [which uses temperature changes or other processes]. It just takes a few minutes to double a sample. A few more minutes, you double it again. Very quickly, you have thousands or millions of new copies."
This ability to duplicate quickly and easily is a positive trait. But, of course, there's also the potential for danger. Does encoding on DNA, the very basis for life, present ethical issues? Could it get out of control and fundamentally alter life as we know it?
The chance is there, but it's remote. The first reason is that storage could be done with only two base pairs, which would serve as replacements for the 0 and 1 digits that make up all digital data. While doing so would decrease the possible density of the storage, it would virtually eliminate the risk that the sequences would be compatible with life.
But even if scientists and researchers choose to use four base pairs, other safeguards are in place that will prevent trouble. According to Ceze, the computer science professor, the snippets of DNA that they write are very short, around 150 nucleotides. This includes the title, the information that's being encoded, and tags to help organize where the snippet should fall in the larger sequence. Furthermore, they generally avoid repeated letters, which dramatically reduces the chance that a protein could be synthesized from the snippet.
"In the future, we'll know enough about someone from a sample of their DNA that we could make a specific poison. That's the danger, not those of us who want to encode DNA for storage."
Inevitably, some DNA will get spilt. "But it's so unlikely that anything that gets created for storage would have a biological interpretation that could interfere with the mechanisms going on in a living organism that it doesn't worry me in the slightest," Goldman says. "We're not of concern for the people who are worried about the ethical issues of synthetic DNA. They are much more concerned about people deliberately engineering anthrax. In the future, we'll know enough about someone from a sample of their DNA that we could make a specific poison. That's the danger, not those of us who want to encode DNA for storage."
In the end, the reality of and risks surrounding encoding on DNA are the same as any scientific advancement: It's another system that is vulnerable to people with bad intentions but not one that is inherently unethical.
"Every human action has some ethical implications," Zhirnov says. "I can use a hammer to build a house or I can use it to harm another person. I don't see why DNA is in any way more or less ethical."
If that house can store all the knowledge in human history, it's worth learning how to build it.
Editor's Note: In response to readers' comments that silicon is one of the earth's most abundant materials, we reached back out to our source, Dr. Victor Zhirnov. He stands by his statement about a coming shortage of silicon, citing this research. The silicon oxide found in beach sand is unsuitable for semiconductors, he says, because the cost of purifying it would be prohibitive. For use in circuit-making, silicon must be refined to a purity of 99.9999999 percent. So the process begins by mining for pure quartz, which can only be found in relatively few places around the world.
Urinary tract infections account for more than 8 million trips to the doctor each year.
Few things are more painful than a urinary tract infection (UTI). Common in men and women, these infections account for more than 8 million trips to the doctor each year and can cause an array of uncomfortable symptoms, from a burning feeling during urination to fever, vomiting, and chills. For an unlucky few, UTIs can be chronic—meaning that, despite treatment, they just keep coming back.
But new research, presented at the European Association of Urology (EAU) Congress in Paris this week, brings some hope to people who suffer from UTIs.
Clinicians from the Royal Berkshire Hospital presented the results of a long-term, nine-year clinical trial where 89 men and women who suffered from recurrent UTIs were given an oral vaccine called MV140, designed to prevent the infections. Every day for three months, the participants were given two sprays of the vaccine (flavored to taste like pineapple) and then followed over the course of nine years. Clinicians analyzed medical records and asked the study participants about symptoms to check whether any experienced UTIs or had any adverse reactions from taking the vaccine.
The results showed that across nine years, 48 of the participants (about 54%) remained completely infection-free. On average, the study participants remained infection free for 54.7 months—four and a half years.
“While we need to be pragmatic, this vaccine is a potential breakthrough in preventing UTIs and could offer a safe and effective alternative to conventional treatments,” said Gernot Bonita, Professor of Urology at the Alta Bro Medical Centre for Urology in Switzerland, who is also the EAU Chairman of Guidelines on Urological Infections.
The news comes as a relief not only for people who suffer chronic UTIs, but also to doctors who have seen an uptick in antibiotic-resistant UTIs in the past several years. Because UTIs usually require antibiotics, patients run the risk of developing a resistance to the antibiotics, making infections more difficult to treat. A preventative vaccine could mean less infections, less antibiotics, and less drug resistance overall.
“Many of our participants told us that having the vaccine restored their quality of life,” said Dr. Bob Yang, Consultant Urologist at the Royal Berkshire NHS Foundation Trust, who helped lead the research. “While we’re yet to look at the effect of this vaccine in different patient groups, this follow-up data suggests it could be a game-changer for UTI prevention if it’s offered widely, reducing the need for antibiotic treatments.”
MILESTONE: Doctors have transplanted a pig organ into a human for the first time in history
A surgeon at Massachusetts General Hospital prepares a pig organ for transplant.
Surgeons at Massachusetts General Hospital made history last week when they successfully transplanted a pig kidney into a human patient for the first time ever.
The recipient was a 62-year-old man named Richard Slayman who had been living with end-stage kidney disease caused by diabetes. While Slayman had received a kidney transplant in 2018 from a human donor, his diabetes ultimately caused the kidney to fail less than five years after the transplant. Slayman had undergone dialysis ever since—a procedure that uses an artificial kidney to remove waste products from a person’s blood when the kidneys are unable to—but the dialysis frequently caused blood clots and other complications that landed him in the hospital multiple times.
As a last resort, Slayman’s kidney specialist suggested a transplant using a pig kidney provided by eGenesis, a pharmaceutical company based in Cambridge, Mass. The highly experimental surgery was made possible with the Food and Drug Administration’s “compassionate use” initiative, which allows patients with life-threatening medical conditions access to experimental treatments.
The new frontier of organ donation
Like Slayman, more than 100,000 people are currently on the national organ transplant waiting list, and roughly 17 people die every day waiting for an available organ. To make up for the shortage of human organs, scientists have been experimenting for the past several decades with using organs from animals such as pigs—a new field of medicine known as xenotransplantation. But putting an animal organ into a human body is much more complicated than it might appear, experts say.
“The human immune system reacts incredibly violently to a pig organ, much more so than a human organ,” said Dr. Joren Madsen, director of the Mass General Transplant Center. Even with immunosuppressant drugs that suppress the body’s ability to reject the transplant organ, Madsen said, a human body would reject an animal organ “within minutes.”
So scientists have had to use gene-editing technology to change the animal organs so that they would work inside a human body. The pig kidney in Slayman’s surgery, for instance, had been genetically altered using CRISPR-Cas9 technology to remove harmful pig genes and add human ones. The kidney was also edited to remove pig viruses that could potentially infect a human after transplant.
With CRISPR technology, scientists have been able to prove that interspecies organ transplants are not only possible, but may be able to successfully work long term, too. In the past several years, scientists were able to transplant a pig kidney into a monkey and have the monkey survive for more than two years. More recently, doctors have transplanted pig hearts into human beings—though each recipient of a pig heart only managed to live a couple of months after the transplant. In one of the patients, researchers noted evidence of a pig virus in the man’s heart that had not been identified before the surgery and could be a possible explanation for his heart failure.
So far, so good
Slayman and his medical team ultimately decided to pursue the surgery—and the risk paid off. When the pig organ started producing urine at the end of the four-hour surgery, the entire operating room erupted in applause.
Slayman is currently receiving an infusion of immunosuppressant drugs to prevent the kidney from being rejected, while his doctors monitor the kidney’s function with frequent ultrasounds. Slayman is reported to be “recovering well” at Massachusetts General Hospital and is expected to be discharged within the next several days.