Question: What are most of your experiments based on???

Jim Caryl answered on 21 Jun 2011:

Most of my experiments are based on evidence/data. We have a set of data that we can form a hypothesis that describes why we get them, but any good hypothesis should also be predictive, so we should be able to say, “If I add this particular chemical to this particualr bacteria, it will have ……. response.” This will help assure us that our hypothesis is correct, and that it accurately explains the physical data. So we design another experiment to test just this, and based on these data, we can either stick with our hypothesis, or revise it and test it again.

Most of my experiments work this way, except I ask the question, ‘If I put this particular gene into my Staphylococcus aureus, which will make it resistant to a particular antibiotic, will the bacteria grow better or worse that an identical bacteria that doesn’t have that gene?’ In the presence of antibiotic, obviously the bacteria without the gene will die, so the one with the gene will do better – I know this. What happens when we take the antibiotic away? Does the one with the gene suffer because it has an extra gene using energy resources of the cell?

Sometimes it does worse, sometimes there is no difference. Very occasionally it continues to do better, but this needs to be determined for lots of different genes and antibiotics, and in different growing environments too.