Researchers from the Southern University of Science and Technology (SUSTech) and Shanghai Jiao Tong University in China have developed a DNA cassette tape drive that functions exactly as one might expect. The experimental setup, published in Science Advances on September 12, is the first working prototype to combine DNA storage with a physical tape-based medium and a compact seekable drive — a clever attempt to merge the longevity of DNA with the scalability of old-school tape libraries.
Data is encoded into synthetic DNA strands, written to a reel of flexible film, and stored in a cartridge that can be loaded, spun, and addressed like magnetic tape. This theoretically yields petabytes-per-meter density and multi-century lifespan on paper. Still, when the system was put to the test in proof-of-concept experiments, it only managed to write a single 156.6KB file, with each read-write cycle taking nearly an hour.
The tape itself is a 3.5 mm-wide polyester-nylon strip, patterned with high-density barcodes that act as physical file addresses. The researchers printed 5,000 of these “tracks” across a 9-meter loop, giving them individually accessible landing zones for DNA payloads. In principle, the format scales to more than half a million addressable partitions per kilometer, and at full density, the team says each one could hold over half a terabyte of usable data. If you do the math, that’s 362 petabytes per kilometer.
Of course, what’s more important is what the prototype can actually do. To test the full write-read-rewrite loop, the team encoded five small files into DNA. These were deposited onto the tape via a built-in liquid handling system, then recovered using sequencing, deleted, and rewritten. The whole cycle played out automatically in a drive about the size of a lunchbox, complete with reel motors, a microcontroller, and an optical barcode reader.
Readout was painfully slow. The test file recovered in the demo was just 156.6KB and took roughly 25 minutes to extract and process. Rewriting that data took another 50 minutes. While the team estimates they could seek to 1,570 different tracks per second, the sequencing and synthesis steps are orders of magnitude slower. So while you can spin the reel like an LTO cartridge and instantly locate where a file should be, the actual throughput is bottlenecked.
Durability, however, is where the DNA tape fares much better. Each payload is encased in a zeolitic imidazolate framework (ZIF) shell, which protects it from water, UV radiation, and oxidation. That shell can be stripped and reapplied in minutes with no apparent damage to the DNA. Based on accelerated aging tests, the researchers estimate a shelf life of over 300 years at room temperature and tens of thousands of years in cold storage.
"Nonvolatile memory based on semiconductors has reached the limits of Moore's Law, and new media are necessary to store unbelievably large amounts of data," the researchers wrote in their paper, ultimately conceding that DNA synthesis remains a non-starter for scaling their project commercially. Back to the drawing board, then.
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