bio.display

Yesterday we prepared an experiment with Maarten de Smit to try out if bacteria grown overnight in an agar loan, but without the arabinose (thus non-fluorescent) could be triggered to become fluorescent by adding some arabinose to it. We prepared agar with different concentrations of bacteria in it (10, 5 and 2.5μl / 200μl). We also created a series of arabinose concentrations even, to see the rate of change depending on the concentration.

The expectation was that GFP expression should start within about 15 minutes of the arabinose added to each well. (The small compartments on the microplate are called wells.)

The result is: nothing.

There could be several things wrong here. One is that the bacteria in the agar gel is already in stationary stage, having had a day to grow and multiply. The other is that they are just too stretched out in the agar – after all, previously we were looking at the effect in colonies.

So the next thing to do is to take a young (2 hour old) liquid culture, where all the bacteria is still active, and add arabinose to some parts of that – and see.