Scientists Stored This Famous Japanese Painting in Protein Molecules

Researchers from Harvard and Northwestern University have stored Hokusai's 19th century woodblock painting “The Great Wave off Kanagawa” using a new method involving protein molecules.

Over the years, scientists have developed techniques to accurately store information in DNA, which if fully developed, could completely change information technology by mitigating the risk of cyberattacks or environmental dangers such as fires or floods that could compromise a computer’s hard drive or a book. But despite advances in the science, the process of storing digital information in DNA remains expensive and time-consuming.

Brian Cafferty, a postdoctoral fellow at Harvard’s Whiteside Research Group and first author on the paper that outlined a new technique, said that the method his team developed is cheaper and less labor intensive. “Think storing the contents of the New York Public Library with a teaspoon of protein,” he said in a press release from Harvard.

Cafferty, who’s a chemist, teamed up with researchers at Northwestern, experts in automation and mass spectrometry, a technique that sorts molecules based on mass using ionization. Their input helped to streamline the process of inputting and reading the information back.

“We set out to explore a strategy that does not borrow directly from biology,” Cafferty told Motherboard. “We instead relied on techniques common in organic and analytical chemistry, and developed an approach that uses small, low-weight molecules to encode information.”

Cafferty’s team used protein molecules called oligopeptides, which are smaller than DNA and can be synthesized more quickly. Caffery says this cuts down on labor.

And depending on how many peptides are bound together, oligopeptides can vary in mass.

To deposit the information, it’s translated using eight-bit American Standard Code for Information Interchange, which means every character (numbers, letters, and in the case of images, pixels) is represented by a group of eight ones and zeros. If a molecule appears in the formation, it is represented by a one, and if it’s absent, it’s a zero. Then, oligopeptides with eight varying masses are arranged on a microwell, a flat plate with multiple, tiny wells, which is then printed on a metal surface where it’s stored.

The team wrote in the press release, “An ‘M,’ for example, uses four of eight possible oligopeptides, each with a different mass. The four floating in the well received a ‘1,’ while the missing four receive a ‘0.’”

In order to retrieve the information, the microwell is viewed through a mass spectrometer, which sorts the molecules by mass and tells them which molecules are there or not.

With this method, a mixture of eight oligopeptides can store one byte of information, and 32 could store four bytes. The team can retrieve the information with 99.9 percent accuracy.

Besides Hokusai’s painting, Cafferty and the team have stored a photo of Claude Shannon who is often referred to as the father of information theory and a well-known lecture made by physicist Richard Feynman.

Cafferty’s team used oligopeptides in their research because they’re varying sizes aided in reading them, but he said the process could be done with any malleable molecules. And the use of other kinds of molecules would ensure that the information encoded could last longer than other methods that we already use, and would take little energy to maintain.

Next, Cafferty would like to try using hydrocarbons, a different group of molecules more stable than peptides. But he says he needs buy-in from other researchers to get them optimized for use on a larger scale.

“This approach appears best suited for long-term storage of our most important information—sets of data that we might want preserved long after our civilization has disappeared,” said Cafferty. “More pragmatically, this method could be used for secure, long-term storage of patients' hospital records or for verification of products along the international supply chain.”