Week 4

This week I did two new things.

Brain sectioning: We had a part of a brain about the size of the palm of a hand, and we needed to slice it into pieces 40 microns thick (which is EXTREMELY thin) so that tests can be done on those. First we had to freeze the brain sample about halfway by placing it on top of a block of dry ice. We do it half way so that we can freeze the rest gradually so there aren't chatter lines when we cut through it with a microtome. After that we used sucrose as a glue to stick the brain to the holding plate on the microtome. We surrounded the brain by powdered dry ice. We set the microtome to 40 microns and began cutting when the brain was frozen enough (if you run your hand over it and it feels like your gliding your hand on glass, then you're good to go). The process took an extremely long time because our sample was about an inch thick and we had to cut it into such small pieces.

We were doing IHC on a TBI rat brain and we had to mount the tissue onto slides. The experience was different then when I had to mount human tissue because I had multiple tissues to mount on each slide, they were so small, and they needed to be put in a certain order. First I had to scoop the brain tissue into a container filled with PB and sort through all the tissue (there were about 15 pieces each). A paper showed the different sections of a rat brain (if it was cut vertically) and I had to sort through all the pieces and put it in that order. It was extremely difficult because the pieces were really small and some were ripped. After that I had to individually mount them onto the same slide. I didn't take pictures but maybe when I go back I can take them because it sounds really confusing in words.

I plan on starting my own experiment either 2 or 3 weeks from now (next week I won't be going because of spring break).