Day 17

November 16, 2011

Today we learned all about Gel elctrophoresis! This technique is used whenever scientists want to sort DNA according to their size. Before we arrived, JM made gel for us to use in the experiment. We placed the gel into a container which was used as a filter that sorts DNA strands. We made many small holes in the gel which was where we would place the DNA strands. We injected 12 microliters of DNA strands each hole. An electrical current was added to the gel and DNA strands. The current caused the DNA strands to move across the gel, but the shorter strands moved faster. This happened for all the different sizes of DNA. The problem was that it takes multiple hours for the electrophoresis to finish so we weren't able to see the final result. While we were waiting for the electrophoresis, we brought some cells that he previously made to the microscope. However, he wasn't able to see the particles for some reason. He assumed that it was because the particles was so small. It was strange though because the particles were attached to fluroescent particles so there should have been no reason why he couldn't see the fluorescent colors. So then he tried putting non fluorescent cells that he hadn't made under the microscope to see if he could see these ones. If that didn't work, that meant that the fluorescent dye was not responsive as opposed to there being a problem with the batch of cells he had made. Luckily, the non fluorescent cells were not visible either so he knew that it was just the fluorescent particles that were not working. It is kind of interesting when he works with the microscope but the only problem is that we aren't able to do anything because the equipment is really expensive and complex and he wouldn't want us to mess anything up. So usually this isn't my favorite thing to do because it also takes a long time for him to focus the microscope correctly while we just have to sit there. But the day did get better once he finished that. I asked if we could go over the protocol again for the electrophoresis just so I had a better understanding. He found this interactive lab online that explained everything step by step. It was so helpful and was fun to do. I was actually just on the website again to help me write my blog!