Week 3 - Sweet Success

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. It was really nice to have confirmation that I am doing something useful with my time this summer. It’s important to have accurate calibration curves because the overall goal of my mentor’s experiment is to determine how pH affects phytoplankton, and to do that we need to have accurate data on what the pH of the cells are. With a calibration curve we can analyze the fluorescence of the cells at certain wavelengths and then plug that value into the equation of our curve and determine what the pH is.

By the end of the week I completed another calibration curve, this time for Thalassiosira weissflogii. When I tested it the predicted and actual pH values were very close for the 6.84 pH buffer and 8.01 pH buffer but the 7.20 pH buffer was noticeably different. However, it was still reasonably close so we determined that it was a good approximation which was good news for my calibration curve. I now consider myself to be basically an expert at using the spectrofluorometer in the lab. I’ve run at least one test on it every day for over a week now. Next week I will continue making more curves for the other organisms that we have cultured in the lab.