Week 4 - More Curves and Experimenting with Esterase

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. In the past she has noticed that SNARF, the dye I am using, is not absorbed by all the cells in a sample, and some absorb more than others. Rachel is experimenting to see if the amount of esterases a cell has influences how well it is able it is able to hold the dye within the cell. We have been using a fluorescein diacetate hydrolysis assay to determine how many esterases are in a cell population. Next week we should be able to determine if old or new cultures, or stressed or unstressed cultures have a difference in esterase activity, and if that would then affect SNARF.