DNA used as rewritable data storage in cells

DNA used as rewritable data storage in cells

They aren’t yet competition for Intel, but bioengineers have created a one-bit “memory” made of DNA that can record, erase and rewrite data within living cells.

One day, doctors might be able to insert such devices into a cancer patient to tally how many times a cell divides and flag when to shut the cancer down. Or researchers might track exactly what happens inside cells as they age.

The work is a step forward in synthetic biology, a new field in which scientists create tools to control life’s basics from the cell on up.

“We can write and erase DNA in a living cell,” says Jerome Bonnet, a bioengineer at Stanford University. “Now we can bring logic and computation inside a cell itself.”

Bonnet and his colleagues, led by Stanford’s Drew Endy, describe the feat in a paper published online May 21 in the Proceedings of the National Academy of Sciences.

Scientists have long dreamed of putting tiny computers inside the body to monitor and perhaps even control what’s going on. But nobody has yet made a silicon-based computer chip small enough to embark on a fantastic computing voyage inside a cell.

So researchers are turning instead to biological tools, such as enzymes and DNA. Some biologists have devised DNA switches that can be turned on and off within a cell. And in 2009, bioengineers reported making a genetic “counter” that could tally the number of times a particular event, like a cell dividing,

But these previous efforts made systems that could write a piece of information only once. Truly useful digital data storage allows the information to be erased and rewritten over and over again, like burning new information onto a CD with each pass. “What we didn’t have is some kind of logic that also has memory,” says Pakpoom Subsoontorn, a graduate student on the team.

The researchers chose DNA as the stuff of memory and used enzymes called recombinases as the tools to flip it on and off. Those enzymes came from bacteriophages, which are viruses that infect bacteria. These viruses use one enzyme to integrate into the genome of the bacterium they’re infecting.