If the week before brought tears per misadventure with a paper-cutter, this week brought laughter as my experiment self-destructed comically. Yes, I am evading responsibility here because the destruction in question happened when I was out of the room, entirely on its own.

If you have been following this latest thread (and if not, you may start here), then you will know that these experiments are designed to measure the growth kinetics of maize roots. I put five seedlings on an square Petri plate containing agar. I use agar because it is 99% water and yet solid. The water keeps the roots moist and the “solid” means I can place the plate vertical, so the roots can grow straight down, as they like to do. An added boon, the agar is transparent so I can place the plate in front of a camera and image the roots through the agar. The camera is hooked up to a computer, which is programmed to capture images at defined time intervals, from which later on I can measure root growth rate.

While in general the setup is working fine, the results so far show that the during the start of the time course, the roots grow slowly. I solved part of the problem by ditching the toxic towels, but I want to see if the entire slow growth problem can be solved by trying a few more things.

On Thursday, I tried one of those thing: A different way to put the supporting tissue paper over the roots. Previously, I dipped the whole tissue in a beaker. This got it good and wet; but, putting it over top the roots always introduced few wrinkles, which can interfere with measurement. This time, I pipetted water onto the surface of the plate, around the roots, and added a dry tissue, flat and wrinkle-free. Then, I pipetted more water onto the tissue to moisten thoroughly. That worked, as far as I could tell. I put the plate in position in front of the camera, hit the “acquire” button, and let the technology run its course.

The next day, I went into the red room to get the plate of seedlings, the last image having been acquired sometime in the middle of the night, tidy up the room, and copy the movie onto a thumb-drive for subsequent measurement. But oopsy-daisy: the plate had fallen over (Figure). A perfect face-palm, other than the fact that a Petri dish has neither a head nor a hand. I checked the movie and of course this happened before the second image was acquired. Not even one time interval to measure. Watching this movie gave me and the members of my lab a good laugh.

Also, as evident in the figure, the new method for handling the tissue paper stinks. Wrinkles everywhere, big ones. OK then, back to plan A for handling the tissue paper.

I took the trouble to find a larger “door stop” to brace the plate in place. With hindsight, it is oh-so-clear that the piece of metal I had been using is too lightweight. And so on Monday, I will set up a new batch of seeds and, as usual, do it all again.