The Ultimate Mixtape Stores 60 Billion Photos on a Single Cassette

If you’ve got too many photos and documents stored on your home computer, don’t pull the trigger on that cloud storage subscription just yet. Maybe a cassette tape that stores 362,000 terabytes of data would do the trick for you instead? As impossible as this may sound, that is exactly what a group of researchers at the Southern University of Science and Technology have created.

This is obviously not a traditional cassette tape of the sort that a Commodore 64 might have slowly loaded a few kilobytes of data from in the 1980s. Rather, the team has developed a cassette tape that is loaded with synthetic DNA adhered to a plastic backing. It stores data in the four nucleic acids that make up DNA, which allows it to be packed extremely densely. With a length of one kilometer, the team estimates that the tape could hold about 60 billion digital photos.

The idea of storing data in DNA is not new. Digital files are ultimately made up of 1s and 0s, just as DNA is made up of four chemical bases: adenine, cytosine, guanine, and thymine. By assigning specific binary patterns to each base, researchers can encode images, videos, and documents into synthetic DNA strands assembled in a laboratory. Previous demonstrations have shown impressive density, but they often lacked the ability to easily locate, modify, or retrieve individual files.

What makes this new system different is that it behaves much more like a real file system. The DNA is deposited onto a long polyester-nylon tape that is printed with barcodes along its length. These barcodes act like files, dividing the tape into more than half a million distinct data partitions per kilometer. As the tape moves through a cassette-player-like drive, a camera reads the barcodes at high speed and identifies the exact location of the desired file.

Once the correct spot is found, the machine briefly dips that section of tape into a chemical solution that releases the DNA stored there. The DNA can then be sequenced and decoded back into its original digital form. The same system can also remove old DNA strands, encapsulate new ones, and write them back to the tape, allowing files to be deleted, replaced, or reorganized without human intervention.

To ensure long-term durability, the DNA strands are stored inside metal-organic frameworks, microscopic cages made from zinc ions. These structures protect the DNA from environmental damage and help preserve the data for centuries. According to the researchers, the tape could retain data for more than 345 years at room temperature, or up to 20,000 years if kept at freezing conditions.

Despite its staggering capacity, this DNA cassette tape is not about to replace your hard drive. Synthesizing DNA remains expensive and slow, and retrieving a single file currently takes around 25 minutes. The hardware involved is also far from consumer-friendly. Still, the researchers see this as a glimpse of a future where massive archives of both frequently accessed “warm” data and rarely used “cold” data could be stored compactly, reducing the need for energy-hungry data centers. Only time will tell if this dream pans out in reality.