Monday 28th October - Friday 1st November
This past week has been a particularly busy one for me. I had hoped to make real progress with the Literature Review but, as all my practical work seemed to come at once, this had to go on the back burner for a while. That is a recurring theme in scientific research - the importance of being flexible and to have plans leap out of the window (especially when your supervisor thinks of another useful assay to do)... nevertheless I have learnt many new skills this week, all of which I will need for my project to come.
I have been performing lots of germination assays on Orobanche and Striga, to see which will be the best races to use for the project. It was just as well; one strain of Orobanche was hopeless, with only about 1 in every 100 seeds showing any response to the germination stimulant, whereas another was really excellent, even though the seeds were actually older. I also had a long chat with Anne, whose PhD forms the basis of the work I will be doing, about the statistical methods she used to analyse her data. Oh dear, my head was spinning after that session...
My favourite part, however, was learning how to cut
ultra-thin sections with the cryo-ultramicrotome. As I haven't got any
infected rice or sunflower roots yet, I was practising on wheat seeds.
It is cold work, as the knife is set at 14 degrees below freezing, and
also slightly dangerous. "That Knife is so sharp" Professor Burrell (the
Mass Spectrometry expert and one of my supervisors) "you will cut
yourself before you know it". Such a fearsome blade is necessary to cut
the ultrathin sections required for mass spectrometry - only 50
micrometres thick (where a micrometre = 1 millionth of a metre). After
mounting the sample, the handle is turned and the sample slowly drops
down onto the blade, which removes a section of the specified thickness.
Turning the handle then advances the sample by the section thickness,
ready to cut the next slice. It was tricky getting used to it - my thin
sections kept curling up - but I did manage to mount some on sticky carbon tape in
the end. These have been frozen in liquid nitrogen, to use on the MS
later.
Photos:
1. The cryo-ultramicrotome
2. Taking the section...carefully now
3. Final sections mounted on carbon tape
On Friday, I finally infected my young rice plants with Orobanche. This was a very simple process in the end - the seeds of the parasite are suspended in water and brushed on with a paintbrush. It took several hours though, leaving me exhausted at the end of it. Now the plants are back in their rhizotrons in the growing chamber and I shall leave them for two weeks, during which the unfortunate rice plants will hopefully be invaded by Orobanche. To finish this week, I popped back home to Solihull for the weekend to catch up with friends, family and neighbours, which was wonderfully restorative.
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