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DON’T TAKE THIS the wrong way, but you’re just
data. Genes built you, from the tips of your toes to the crown of your head. In
that sense, you’re not unlike a computer: Code produces the output that is your
body.
In fact, for the past two decades, scientists have
used actual DNA as if it were literal code, a process called DNA
computing, to do things like calculating square roots.
Today, researchers report in the journal Nature Communications that they’ve deployed DNA to detect
antibodies—soldiers your body produces to fight viruses and
such—by running a sequence of molecular instructions. Someday, the same
kind of calculations could automatically release drugs in response to
infections.
The key to making it all work is
that DNA strands really like to stick to each other—in very specific ways. “In
a test tube, you mix a bunch of DNA molecules,” says Maarten Merkx, a biochemist
at Eindhoven University of Technology in the Netherlands and a lead author on
the new paper. “By choosing the sequences right, they undergo a series of
reactions.” A single strand from one double-helical molecule of DNA attaches to
a strand from a different DNA molecule, a process
called hybridization that creates a new DNA molecule, which in turn
combines with yet more DNA in the mix. Think about what happens if you mix
orange juice and champagne: You get something novel and quite frankly better.
Critically, certain combinations of
certain DNA molecules happen only in the presence of an antibody. If you add
together the right molecules, you can get a signal out of the system when that
particular hybridization happens. That’s kind of like what happens in a
computer cranking code; hybridization is the “yes” or the 1 and a lack of
hybridization is a “no” or the zero. In this case, the scientists added
ingredients so that the DNA would fluoresce if the hybridizations happened just
right—that’s the output.
Sure, you can test blood for
antibodies. That’s the old fashioned way. The idea here is to one day use DNA
computing as a persistent monitor for antibodies. You could use that setup to
create DNA nanocapsules carrying drugs. “The DNA that our DNA computer
produces can be used to unlock this capsule,” says Merkx. His team was looking
specifically at viruses like influenza and HIV, so maybe the package could
deliver more virus-killing antibodies.
The study also represents a leap in
how DNA computing works in general. “It certainly offers another tool in the
toolbox of those who want to design complex computing strategies,” says Philip
Santangelo, a bioengineer at Georgia Tech who wasn’t involved in the research.
“You could use proteins and enzymes to build computing architectures that use
many biomolecules, not just DNA.” More complexity means more precision and
sophistication in the kinds of programs scientists can run.
So sure, you may just be data. But
in the right hands, that data could one day do wonders for medicine.