Lauren Roof's blog

It’s crazy how fast my time at this internship has gone. Everything is wrapping up now. I spent most of the week preparing my research poster since I was presenting to my lab group in our meeting on Friday. I’ve never made a research poster before so I was a bit confused at first. Once Rachel helped me get started I began to enjoy the chance to get creative. The lab meeting was an opportunity to practice what I would say, and to get feedback on my poster. I got a lot of great comments on it, so I’m feeling confident that I’ll be ready to present next Friday to more people.

The bulk of this week was spent gathering data from the pHstat. Since the experiment last Friday went well, Rachel decided to start a pH gradient experiment. For this kind of experiment, the computer generates a sine curve that has an amplitude and frequency that we set. The experiment is supposed to reproduce the natural pH cycle present in the ocean due to changing carbon dioxide levels throughout the day. When the sun is out and the phytoplankton are performing photosynthesis, the carbon dioxide decreases, so the pH decreases.

Once again, I worked on many different projects this week. Every day I come in I never know what I’ll be working on since Rachel and I have so many different experiments we want to run. On Monday and Tuesday I mostly worked with the flow cytometer. I made a new calibration curve for T. weiss to compare to the old one, and it was very different. The slope for one line was positive and the other one was negative. I ran a test with randomly made buffers to see which line would be more accurate but they were both terrible. The second one I made was off, but the first line was extremely off.

This week got off to a fun start when I joined the other IEH interns on a field trip to the gorge. It was a beautiful sunny day which was perfect weather for viewing waterfalls. One of my favorite parts turned out to be the tour of Bonneville Dam. My previous knowledge of hydroelectric power was basically what I remembered from grade school, which was barely anything, so I learned a lot from the tour. I learned about the history of the dam, how fish ladders work, how the turbines work, and perhaps most importantly, that I really do not want to work as a fish counter for a dam.

I have surprising news to share this week—I made more calibration curves! The curve I made this week was for Thalassiosira pseudonana. It should have gone smoothly since I’ve made a bunch of these by now, but the data looked a little funky. The spectra didn’t have big chlorophyll peaks and the isobestic point was off. Ideally when working with SNARF all the spectra of the different pH should cross at one point which is the isobestic point.  The spectra I got all converged around the same point but it wasn’t as close as prior data that I’ve collected.

I started off the week making calibration curves for two more organisms. I’ve gotten quick enough with the process that I can make a curve and test it on the same day now. On Thursday I was able to go out into the field with another grad student in the lab, Brittany, and see how water samples are collected. We went out to a site on the Columbia River and it was gorgeous! I enjoyed being able to get away from the lab for a day and feel the sunshine. The lab is so dark and cold that usually by the end of the day I've forgotten that it's summer. I also helped Rachel with her esterase project.

This week got off to a great start! I finished making my calibration curve for Alexandrium fundyense and it proved to be an accurate curve.  It was tested by making samples with three randomly made buffers of varying pH and analyzing their fluorescence after adding the dye to them. Then we compared what the curve predicted their pH values to be to what their actual pH values were. The predicted values were very close to the actual values which meant that I accomplished something! The data I collected resulted in an accurate calibration curve.

I started working on my main project for the summer this week. I will be building calibration curves for different phytoplankton to measure the pH of the cells using a fluorometer. To make the curve I prepared samples of the phytoplankton by putting them in different buffer solutions so that their pH will be known. Then I added a dye called SNARF to the samples which is what fluoresces according to the pH of the cell. Preparing the samples for the fluorometer is a very time consuming process, so I have learned that patience is key.

This week has mostly involved me trying to store as much information as possible from the huge amount that is being thrown at me every day. I am working with Rachel, a PhD student, to study how pH affects phytoplankton, particularly a toxin producing kind known as Alexandrium. The one thing I truly have ingrained in my brain after my first week is how to wash the laboratory equipment. No matter how much washing I do one day, there is guaranteed to be plenty more to do the next.