Living Cells Can Now Be Used to Build a Computer

In the course of the past year, my mind's been blown so many times by breakthroughs in biotechnolgy that I wasn't even surprised when I read about a bunch of MIT researchers building a computer out of living cells. After all, scientists can now store data on a single molecule or, if that's not small enough, a single strand of artificial DNA. Some are also working on invisible microchips made of carbon nanotubes, and doctors are already talking about using nanotechnology for everything from monitoring organ functioning to zapping cancer cells.

So somebody in Cambridge must've thought, "Why not just combine our powers and just build a computer out of living cells?" And that's exactly what's happening. The more I thought about it and read about other attempts, the more I realized that this could be the breakthrough of a generation, a new way of computing that could change everything. Consider my mind blown once again.

As wild as it sounds, the basic idea behind a living computer is pretty straightforward. Computers are simply devices that can process data, perform calculations, and deliver an output when given an input. Your brain is a computer. So is the mid-nineties Packard Bell minitower sitting in your parents' basement. So is the Antikythera mechanism, an ancient analog device that the Greeks built back before Jesus was born.

And in their own way, living cells are perfectly engineered to take on basic computing tasks, since they're filled with DNA that, among other things, can store information and activate certain proteins. These are the exact functions that this group of researchers from MIT are focusing on in their attempt to build a computer out of living cells.

This new bio-computer uses living cells to perform calculations, but it's not entirely natural. The MIT researchers built so-called DNA modules out of circular strings of DNA that they implanted in E. coli cells. The input comes in the form of recombinase enzymes that either turn on or turn off DNA sequences, effectively enabling them to work like the Boolean logic gates that control the basic functioning of electronic computers.

"These developments will more readily enable one to create programmable cells with decision-making capabilities for a variety of applications," said Boston University synthetic biologist James Collins, who was one of the first to tackle the challenge of building a living computer but didn't participate in the MIT study. He did, however, lay the groundwork for the technology a few years ago when he created a genetic "toggle switch" that's at the heart of the latest efforts.

Indeed, scientists have been working on the basic building blocks of bio-computing for years. The new MIT approach brings something new to table, though: memory. Christopher Voigt, one of the MIT synthetic biologists, described the process as "a very digital and permanent way to store information in DNA. The logic can store multiple experiences — for example, if the cells had encountered two environments and in what order."

But that's not all. "[The change] is permanent," he said. "After the cells die, the information can still be retrieved from the DNA." These artificial modules are like the Gmail of bio-computing, only better. There's no need to delete information if it can be archived for the rest of time.

So what's this new technology good for? Right now, it's great for impressing geeks like me. As scientists continue to perfect the modules and processes, however, the future of bio-computing could bring some major breakthroughs in medicine and, for lack of a better term, exploration. The two are sort of linked and both are pretty out there.

Basically, bio-computers would be able to go places that regular computers couldn't go, like the bottom of the ocean or the inside of your body. This feature comes in handy when thinking of ways to create better, more non-intrusive treatments for all kinds of medical problems. A properly located bio-computer, for instance, could switch on at the sign of an illness and deliver drugs without the patient even needing to go to the doctor.

That's just one example of the amazing possibilities of living computers. There are plenty more, though, enough to fill an entire book. All you really need to know, though, is that advances in biotechnology are reaching a critical mass, making the seemingly impossible sound like a weekend in the Hamptons. I know that analogy doesn't make a ton of sense, but I had to find some way to express how ridiculously expensive all this research must be.