DNA Is Tougher Than You And There’s Science To Prove It

As we’ve heard from the Mythbusters, the only difference between screwing around and science is writing it down.

Well, kids, sometimes scientists try things just because reasons. For instance, some molecular biologists at the University of Zurich who were already sending up a sounding rocket to do gravity tests on DNA decided to smear a couple of samples on the hull of the rocket, for laughs. Except they wrote it all down and published it, which is mostly the difference between you strapping stuff to bottle rockets and what people with research grants do.

They were curious to see how much, if any, of the cells would survive low earth orbit. What they found was slightly alarming.

Not only did over half the samples survive re-entry in to the Earth’s atmosphere, over a third of the DNA was still usable.

“We were totally surprised. We never expected to recover so many intact and functional active DNA,” said Cora Thiel, lead author on the study. “Our findings made us a little bit worried about the probability of contaminating space crafts, landers and landing sites with DNA from Earth.”

Sounding rockets are used for short experiments that need to be carried out in space. The one in this test, for instance, was only out for 13 minutes. The plasmids that were sent up in this flight were of two different genes, one that provides antibiotic resistance to bacteria, and one that encodes green flourescent protein. (Plasmid DNA is not the same as chromosomal DNA, and is about 10 times smaller than bacterial DNA.)

When the samples came back they were still able to make bacteria strain resistant, and stuff glow green. The possibility that we’re sending the material to make life on other planets accidentally, by not sterilizing the hardware we send out well enough, is apparently very real.

Sequencing the DNA revealed that it didn’t contain more than a handful of mutations, which may or may not be a result of its time in space.

“We cannot say how these big chromosomal DNA molecules would react under the same conditions and this should be investigated in a separate experiment,” said Oliver Ullrich, the biochemist who co-authored the paper. “However, we speculate that small plasmid DNA molecules might be more resistant to re-entry conditions than chromosomal DNA, which is also packed with proteins.”

So this means we’re going to have to launch more rockets squirted with DNA. And that’s too much double entendre for me to deal with on a Monday.

Via Ars Technica and Space