Sharanya Entry #4-Week #5

It's hard to believe that I only have a week left at the Goes lab. This past week has definitely been the busiest and gone by the fastest. I may have mentioned this before, but there are two separate experiments happening at the same time and on Monday, my partner and I had to help the other group with their experiment since Monday is their sampling day and Thursday is ours. From 9 AM to 6 PM, I was filtering fifty samples of culture, each with one of the four different trace metals in order to collect chlorophyll measurements. My partner was busy using the FIRe to measure fluorescence. Something that I may not have mentioned before is that my PI gave us questions to answer for homework over the course of the experiment and finally we all had a little Q&A session where he asked us what the answer to those questions were. Some of them were pretty straightforward while others were a bit more challenging. Tuesday was also a bit busy since our group had to do cell counts five times for each bottle in duplicates. We found that the counts significantly increased for two of the four prey species. The "50 Noctiluca+Peridinium's" numbers jincreased from an average of 34 and 51 cells per 3mL of culture to an average of to an average of 53.6 and 63.4 while the "50 Noctiluca+Tricornutum's" bottle increased from 34 and 24 cells to 48.6 and 51 cells.

Cell Counts 7/19/2016

Cell Counts on 7/21/16

This increase shows that the Noctiluca cells actually have a preference for the Peridinium prey species which is also a dinoflagellate, and for the Tricornutum, which is a diatom species. This was different from what I thought would happen. I thought that the cells would prefer the Pyramimonas prey species since they are chlorophytes meaning they contain high amounts of chlorophyll. Wednesday was probably the least busiest day since all our group had to do was make seawater and prepare the labels for the next day's sampling. However Dr. Crider visited my lab and I had the pleasure of introducing her to my lab group and my PI. I also explained to her what my project was in the lab and also showed her some of the equipment that we used to calculate things like chlorophyll, ammonia, and fluorescence. We then Ubered our way back to city and met up with David, Will, and Alex for lunch at the Community Restaurant on 116th Street. 

Finally, Thursday was our sampling day. However this time we had to label forty-eight bottles for ammonia and another forty-eight for nutrients. So instead of only doing ninety-six bottles for samples, we actually had to sample double that amount! Initially, I was overwhelmed with the amount of work we had that day and was wondering whether we would finish all 196 bottles in time to catch the shuttle back to NYC. The first two duplicates of bottles contained Peridinium and Tricornutum respectively so we spent a lot of time (two hours) trying to get through those and not make any mistakes that might compromise our results. Fortunately, my partner and I realized that after the first two bottles, the rest were pretty easy since there weren't as many cells inside and they were significantly easier to sample. The easiest to sample was definitely the Pyramimonas culture since the cells were larger than most and also contained more endosymbionts. They were easier to spot during cell counts and were also easier to pick with the pipette. Concurrently, as my partner and I were sampling the other group was helping us by filtering our chlorophyll samples and operating the FIRe machine. Basically, we use the FIRe to measure fluorescence by measuring both MT and ALS measurements and adjusting the GAIN values. Normally, most of our samples fluctuate around a GAIN of 2,000. Those that contain the media (blanks) would have different GAIN's due to the lack of Noctiluca cells. For these values, we would only measure the MT value and ignore the ALS value on the monitor. In the end, we were surprised to finish only an hour late and were able to catch the 6 o'clock shuttle. 

Sadly, this week was the last week for doing any hands-on work and Thursday was our third and final sampling day. I have really enjoyed learning about and how to operate all of the different methods. This upcoming week will mostly be analyzing and organizing our data for our research paper and posters. While I will miss the hands-on experience of experimenting, I am looking forward to fully understanding and synthesizing the details of our data so that it is ready to be presented.