Making Gels

Last time I was at the NYSM, I used the PCR machine to replicate DNA. Today, I took the samples that we replicated and made a gel with them. We assembled various substances to make the gel. One of the ingredients was this fluorescent dye that makes the DNA within the gel visible under the black light. Within the gel form, we put in combs, which are plastic comb shaped inserts that go into the gel and make about 25 grooves in the gel. We waited for 5-10 minutes for the gel to solidify. While we waited, we added this dark dye to each of the 9 samples so that they would not only be visible but also to add density. The next step took a lot of patience, precision, and a steady hand. I had to take 5 micro liters of each sample, using a pipette, and insert them individually into each groove within the gel. The gel was submerged with one liquid below it and one liquid above it. My depth perception has never been great, so placing the pipette in the exact location, making sure not to penetrate the gel was a bit tricky. After all was in place, we had to run the gel through an electrical current. DNA is negative, so by running a current that ran negative to positive, the DNA would move along with it. Because of the dyes, we could see 3 separate color lines forming. After it was done, we took the gel over to a machine that exposed the gel to the correct lighting and then could take a picture and process it through a computer. We need to do this because the picture will show bright lines on certain areas where it was positive. Unfortunately, the photo was all negative. This means that something must have gone wrong somewhere along the lines. Disappointing, but not the end of the world. In the next ten minutes, I made up new test tubes to go through the PCR machine. Next time I go, we will give the gel another shot.
Since we had an extra half an hour, Dr. Cryan went into the freezer and pulled out some insect samples. We looked through microscopes and separated the mix of all different shapes, sizes, and colors into what appeared to be categories based on species type. It was amazing to see the tiny insects under a microscope. A little weird at first, but then I got to see the different features each species had and Dr. Cryan told me what the features did. It was amazing to see some insects that had only recently evolved to have a different feature and then comparing it to the insect it used to look like.