Day two was just as action packed as the first. The anticipation from the first day was slowing wearing off, and I felt ready to work. I started off the morning hearing about the results from the previous days experiments which led to the plan for today’s work. Almost immediately after my arrival, I headed into the EM (electron microscope) room with Dr. Bermek. I had gotten a taste of the EM yesterday, but today it was like I was eating a three course meal. Dr. Bermek loaded a grid which required lots of precise and intricate detail to move the spec sized grid, put it in the right place on the tip of a long metal wand looking piece of equipment, and put the wand shaped piece of metal into its correct spot on the EM. Since it took a little while to get loaded she showed me how to switch between the two computers in front of us which made my task a little more daunting because I had to worry about working with two different programs.
Once the EM, was loaded she showed me how to focus the beam – another tricky aspect of the EM. There were so many controls it felt like I was sending a space ship into outer space. She first showed me the magnification which was pretty self-explanatory except it worked in accordance with another control – the intensity. Whenever I changed the magnification I also had to change the intensity. I had to make sure not to move the magnification to quickly or too much or the beam would be too wide for the etched circle on the plate, and I wouldn’t be able to see anything. The next control she taught me was the one that allowed me to look at different parts of the grid. There was also a button called R1 which I would press when I was finished choosing the part of the grid I was looking at, and it moved the bottom of the plate upwards so I see the sample we were analyzing. The first sample we were looking at was the DNA which was the control. My job was to analyze the sample by counting the number of super coiled, relaxed, and “other” stands of DNA that appeared. After showing me the basics of the EM controls and the features on the computer, Dr. Bermek left me to count while she continued working on a different experiment. I was a bit hesitant when she left because I didn’t trust myself with a machine that costs more than college tuition, but she had set up everything so well I felt prepared, and I was very cautious. As one sample after another went by I felt more comfortable. I used a handy counting machine that made the process a little easier because on some samples I was categorizing over 400 DNA strands. The hardest part was figuring out where I was on the sample because it all looked the same, and I didn’t want to accidently count a DNA strand twice. It was really neat to see up close what super coiled and relaxed DNA look like. Some grids had a UL8 protein while others had topoisomerase. The different solutions added caused the super coiled DNA (what its normally like) to become more open looking by uncoiling it.
Once I had finished counting the results from mini grids, Dr. Bermek asked me to drop spread some more grids. It made me feel really important because she left me to do it by myself while she worked on something else. I used the same technique from yesterday where I dipped each grids in various solutions and then immersed it in 75% ethanol for 30 seconds and then 80% ethanol for 45 seconds. Once I was done preparing the samples, we looked at a few more things through the EM, and just like that my second day was already over. It was super cool to work so closely and independently with a electron microscope, a piece of material super intricate but really useful. I was also glad I could help Dr. Bermek with the preparation for other experiments. It felt like I was really working in the lab. Day two was just as informative and action packed as the first. I can’t wait for tomorrow!
My handy dandy counting tool.
Examples of what some of the DNA strands I counted looked like.
My Drop Spreading layout.
Up-close example of the tiny grids after they were prepared.
My control panel for working and manipulating the EM.