Science Buddies: "Ask an Expert"

Hello! I'm currently working on my AP Research experiment. I'm exploring how sudden heat shock at different temperatures will affect Saccharomyces cerevisiae yeast agar plate growth.
I'm still uncertain on the data collection/analysis collection of the project. For one, how would I be able to quantify the growth of the yeast without using a hemocytometer? It is something that I'm not in possession.
Other than using a hemocytometer, I've seen some people advise to use an image-processing module online to count the cells. I'm leaning towards this, as it sounds more efficient.
So, I was wondering if there was a more accurate form of yeast cell quantification that does not require a hemocytometer. Also, I wanted to know which mathematical equations I would need to use in order to measure the rate of growth, possibly even compared to temperature. Thanks!

Hello!

You might find this resource helpful. It's a step by step guide to using an online image processing program called ImageJ to quantify yeast growth and survival on agar plates. These instructions will hopefully give you the information that you're looking for!

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7757406/

If you want to measure yeast growth in your liquid cultures, you can measure the optical density of the cultures using a spectrophotometer. If you don't have access to one, you can build a rudimentary version of one yourself at home using this guide from Science Buddies:

https://www.sciencebuddies.org/science- ... photometer

I hope this helps!