Seriously though, I know I need more rest as I keep making stupid mistakes. I managed to plan my next experiment so that the time to infect my plants was when i was actually out of the country ( fortunately I managed to rescue the plates of seed I had prepared by breaking the dormancy cycle earlier, moving the infection date to the day before my flight), I dropped my access card and didn't even realise until i received an email telling me it had been handed in, I left my watch behind one day...and then there was the incident with the microtome...
Slicing off a new section from one of my samples - delicate work as the sections are only 10 microns thick ( a micron being a millionth of a metre).
One of my ongoing experiments is to piece together an exact timeframe of the process by which Striga gesnerioides infects an Arabidiosis host. Although this is well known for Striga hermonthica, much less work has been done on gesnerioides so I have been harvesting tissue samples from infected host plants every few days, all carefully labelled so that I can trace them to the date they were collected. I am slowly working my way through them, embedding them in Technovit resin before slicing them into thin sections with the microtome so that they can be viewed under the microscope. Being an expensive bit of kit, one of my lab colleagues, Peijin, gave me a training session, showing me how to load the sample and lower it down onto the blade to slice off a delicate semicircle of embedded tissue. It was quite thrilling to prepare my first slides and have a look under the microscope!
This week, I tried to go it alone for the first time. Sample loaded, settings adjusted, all ready... but when I lowered the sample down - disaster! Instead of a wafer thin slice, a whole chunk of my sample came off, leaving me with fragments of Technovit and no sample. What was the matter? Did the angle of the blade need adjusting? I moved the blade holder back and forth, fiddled with the section thickness settings and adjusted the sample positioning but to no avail. My sample was becoming increasingly wrecked as flakes were sawn off apparently at random. I decided to give up and returned to the lab. Seeing me looking so glum, Peijin offered to come and have a look at the microtome. At first she was perplexed as I was until she took the blade holder out for a closer inspection.
'oh...' She said 'there isn't actually a blade in here...'
In my dopey state, I hadn't realised that the blade had been taken out of the holder by the previous microtome user. So I was essentially just bashing my sample against the blunt edge of the holder, which would explain why I couldn't cut a decent section! I was so tired, all I could do was laugh with relief .... And when the blade was actually inserted, I did manage to get some decent sections. I'm hoping to start staining these next week to show the structures of the host root and invading parasite more clearly.
Read this, then sleep:
ReplyDeletehttp://www.famousscientists.org/7-great-examples-of-scientific-discoveries-made-in-dreams/
(I'm certain it works for woman too...)
Thanks for that, truly inspiring! I loved the fossil fish example, especially as I did 'dream' of becoming a paleontologist when I was little ( Jurassic Park has a lot to answer for...). But I found that my enthusiasm for dinosaurs did not translate into a love of rocks... I wonder how Striga gesnerioides would manifest itself in a dream?
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