/The smiling DNA (The tinkerers of DNA, part 1)

The smiling DNA (The tinkerers of DNA, part 1)

Whether we like it or not, and whether we understand it entirely or not, we’ve become incredibly good at tinkering with DNA – the very molecules that make us what we are.

Ever since an acidic compound was discovered in the nucleus of the cell in 1869, and called nuclein, our abilities to play with it were growing sometimes even faster than our understanding of why do we succeed in doing so.

In the history of DNA the advances in genetics and genomics grow exponentially the closer we come to present days. It took almost 100 years after we learned about DNA to unveil its structure in 1953, but after the genetic code (ATCG) was cracked in 1966, it took only 20 years until we were able to perform Polymerase Chain Reactions (PCR) in 1986 with which we could snip and stitch any two sequences of DNA we could ever wish for. And from there it was almost overnight in the scale of history of science, until we were able to sequence the first genome (of a bacteria in 1995) and even the whole human genome (which is roughly 1 800 times bigger than the first one to be ever sequenced, and we made it by 2001).

Strangely enough, discoveries and advances related to genetics have been piling up with such speed that scientists and the wide public became overwhelmed with information and couldn’t any more follow through with everything new coming out of the genetics labs. And in the mean time DNA-magicians were keeping busy, pushing the boundaries of science and technology to see how far exactly we can dig into the secrets of one of the most stable organic molecules, and the one that with only four letters writes out the whole instruction manual of every species that has ever lived on this planet.

And all of a sudden DNA wasn’t just the molecule of life any more. It became a tool for nanotechnology and the future of electronics. Nanotechnology has been “the next big thing” for a while now although it’s been taking a little longer than planned to get it up and running. And chemists got to play with DNA the most. The complementarity of the two strands of this polymer made it the dream toy for molecular engineers – they now had an organic molecule which they could force into any fold they wanted simply by engineering its sequence into any imaginable combination of the famous A, T, C, G bases. It could be made to twist, turn, loop, close up or remain open at the will of its creator and respectively the shapes it could be forced into are limited only by the imagination of the scientist. Yet again, it had proven not that easy to manipulate DNA molecules just yet. Scientists were able to engineer DNA sequences at will since the 1980s, but they were limited by the size of the DNA stands the synthesizers could manufacture. In the early 2000s an engineer decided that it will be much more feasible to force DNA strands into structures if he’d use a naturally occurring one – namely a whole viral genome. It took months, but knowing the complete sequence of the viral genome, he could design short stretches of DNA complementary to the regions he precisely identified to staple the viral DNA into a desired shape. He then could view this nano-sculpture with an electron microscope and called it DNA-origami.


DNA-origami smiley by P. W. K. Rothemund, 2010

Those DNA-origami structures could be then used for everything and anything – from drug-delivery machines, to microscopy rulers, but by far the most promising  from economic point of view option is to use them in nanoelectronic circuits. Already companies like IBM had taken up the idea of creating chip circuits based on DNA structures and this is for sure going to be just the begging.