In the Haase Lab I study the model organism S. cerevisiae, or baking yeast. All of the experiments I have performed so far involve growing cultures of different strains of S.cerevisiae in different medias and taking samples at intervals to study how the cells are growing and/or budding. Usually my day in the lab starts at 8:30, when I come in and check on the cultures I inoculated the afternoon before for use in the next day’s experiments. I take samples from these cultures in the water baths, where they are growing in liquid media in flasks, and check them under the microscope for contamination. If there is no bacteria plotting to ruin my day, I count the cell density and dilute some of the yeast down in fresh media in new flasks. If I need to synchronize the cells for the day’s experiments I also add alpha factor, a mating pheromone that prompts the cells to arrest in G1 phase, before I put the fresh cultures back in the water baths to grow. Then I dispose of the cultures from the night before and then go to the Howard Hughes morning meetings if we have one that day.
After the Howard Hughes meetings, my days vary depending on whether or not the Haase lab is going to have a meeting or journal club that day. I will usually come back and check the cultures I diluted that morning, and if there is no contamination I spin down and wash a certain amount of the cells in the centrifuge, transfer them to whatever media that day’s experiment calls for, and start a time course. For the next four hours I will take samples from the growing cultures every 13 minutes. If there is an afternoon lab meeting, I try to hurry and start the day’s time courses as quickly as possible after the HHRF meeting so that I will not have to leave lab meetings to take samples. If there is a lab meeting in the morning I usually cannot do an experiment that day because there won’t be enough time after the meeting to synchronize the cells and run a time course. When I do have a time course going, during the 13 minute intervals between time points I will clean my bench, read research papers (so many research papers), talk with the researchers in the Haase lab, go over my data with Chun Yi- my graduate student mentor- , eat lunch, and count samples.
Counting is when I visualize the yeast samples under a microscope and find the cell density and/or the budding index (ratio of budded to total cells) in the sample. This is the most time consuming and tedious part of my day, but it is important to do and the results are very informative. I am still amazed that we can learn so much about different genes just by growing different mutant strains and counting their rate of budding under a microscope. After I am done with my time courses, I clean up and if there is a lab meeting I head out with the other researchers. After meetings I usually finish counting for the day, plot the results, and discuss the findings and my plans for the next day with Chun Yi. Lastly, if I have any experiments the next day I inoculate the cultures I will need and start them growing in the water bath to be used the next morning.
Overall my days are pretty well structured due to the nature of the experiments I am doing. The people in my lab are very nice and helpful whenever I have any trouble and I am enjoying my experience contributing to the research process.
This is what a hemocytometer, the “instrument” I use to count the yeast cells, looks like under a microscope. The only difference is our microscope is more zoomed in to focus on just one of the little 4×4 squares at a time. When I leave the lab most days if I close my eyes I can see this image… lines and glowing budded yeast floating across my vision.
HEHEHEHE…. Quick google search for “S cerevisiae hemocytometer” and this image was one of the top hits. Not surprised.
