American academics have designed mixtures of metabolites to recreate the binary system, made of 1 and 0. On plates the size of a mobile phone, they managed to record the image of a cat with a rate of 99% success.
DNA strands are not the only organic compounds that could potentially replace our hard drives. Inspired by DNA research, researchers at Brown University in the United States have wanted to test other molecules to evaluate their information storage capacity.
They created mixtures of metabolites, organic substances created by the metabolism containing sugars and amino acids, among others. The idea is to use the presence or absence of specific metabolites to recreate the 0’s and 1’s of binary code. They managed to record and read images of a cat from an Egyptian tomb, an ibex and an anchor.
To record the ibex image, the research team used mixtures of six different metabolites to create six-bit bytes. They then used a robot to drop drops on a plate, with a total of 1,024 drops encoded with the presence or absence of each of the six metabolites. This created 1,024 bytes of six bits, which made it possible to encode the image containing 6,142 pixels in black and white.
The researchers then used a mass spectrometer to analyze the contents of each drop, and identify the metabolites present. This allowed them to read the image data with an error rate of around 2%. They then used an image containing 17,424 pixels representing a cat, which they encoded through mixtures of twelve metabolites deposited on a plate in 1,452 points. They achieved a reading accuracy of 97.7%, which they then improved through logistic regression, to obtain an error rate below 1%.
The binary image data is mapped to a set of metabolite mixtures, each bit determining the presence or absence of a compound in a mixture. © Eamonn Kennedy, Christopher E. Arcadia, Joseph Geiser, Peter M. Weber, Christopher Rose, Brenda Rubenstein, Jacob K. Rosenstein
The plates used to encode the images are 76 x 120 millimeters, a size close to the size of a smartphone. A cumbersome technique in comparison to flash memories. However, this is only a first prototype of research, the researchers said that a storage system made of metabolites could have a much smaller size. Metabolite molecules are significantly smaller than DNA, and more varied, which would allow them to be much denser.
This system, which the researchers say did not optimize, reached a write speed of five bits per second and a reading speed of 11 bits per second. The increase in the number of metabolites used, and therefore the number of bits per point, could considerably improve the reading speed. There are around 100,000 known metabolites, potentially up to 12.5 KB of data per point, although not all of them will be usable, stable enough, or easily identifiable by this method.