Question: What is your favourite experiment and why?

Ciarán O'Brien answered on 13 Nov 2014:

My favourite experiment that *I’ve* done was my research project for the end of my masters degree. I had to look at the DNA of a species of bacteria found living in a sponge off the coast of Galway, and see if I could find the genes that allowed it to make antibiotics that were very good at killing “superbug” bacteria, which are resistant to most drugs and a big problem in some hospitals.

We already knew it made antibiotics because it killed off dangerous bacteria, but we didn’t know where the genes that made them were or how they made the antibiotics. I had to run a whole lot of computer tests on the DNA, and compare it to the DNA of other bacteria, and do a bit of guesswork, but eventually it all paid off and I identified a couple of gene clusters that worked together to produce the different antibiotics.

Now that we know where to find those genes, other scientists can look into swapping them into other bacteria to produce loads of them for use by hospitals with superbug infections!

My favourite experiment that someone else has done has to be the cosmic background radiation experiment carried out in the late 80’s and early 90’s. It was just perfect: They asked a very good question, they planned their experiment very carefully, and the results were so accurate you couldn’t see the margin of error on a graph. It worked beautifully, and pretty much proved that the Big Bang model is the right way to go to work out how the universe began.