DNA cassette tape can store every song ever recorded

Retro cassette tapes may be making a comeback, with a DNA twist. While DNA has been used as an information storage medium before, researchers have now combined this with the convenience and look of a 1980s cassette tape, creating what they are calling a DNA cassette.

Xingyu Jiang at the Southern University of Science and Technology in Guangdong, China, and his colleagues created the cassette by printing synthetic DNA molecules on to a plastic tape. “We can design its sequence so that the order of the DNA bases (A, T, C, G) represents digital information, just like 0s and 1s in a computer,” he says. This means it can store any type of digital file, whether text, image, audio or video.

One problem with previous DNA storage techniques is the difficulty in accessing data, so the team then overlaid a series of barcodes on the tape to assist with retrieval. “This process is like finding a book in the library,” says Jiang. “We first need to find the shelf corresponding to the book, then find the book on the corresponding shelf.”

The tape is also coated in what the researchers describe as “crystal armour” made of zeolitic imidazolate, which prevents the DNA bonds from breaking down. That means the cassette could store data for centuries without deteriorating.

While a traditional cassette tape could boast around 12 songs on each side, 100 metres of the new DNA cassette tape can hold more than 3 billion pieces of music, at 10 megabytes a song. The total data storage capacity is 36 petabytes of data – equivalent to 36,000 terabyte hard drives.

However, says team member Jiankai Li, also at the Southern University of Science and Technology, if you put one of the new tapes into an old-fashioned Walkman, it won’t produce any meaningful sound, because the DNA cassette doesn’t use the magnetic signals of its predecessor.

“Our tape carries DNA molecules,” says Li. “In other words, it would be like trying to play a photo in a record player — the formats are incompatible.”