Science Buddies: "Ask an Expert"

We wanted to try this project idea and I think it would be easy for us with the help of our Microbiology teacher. But we wanted to have a background of this project. Should we have an experimental group of yeasts and zap it with different amounts of x-ray? And how to observe the growth of yeasts? How could we identify if they're still alive and growing? Please help me with this one.

,Hi,


Welcome to Science Buddies! Is this the project idea you are interested in doing? This is a really great project, but it is really difficult:

https://www.sciencebuddies.org/science- ... p030.shtml

The project involves constructing an x-ray machine:

https://www.sciencebuddies.org/science- ... p083.shtml

And then using the x-ray machine to do an experiment on yeasts:

https://www.sciencebuddies.org/science- ... p005.shtml

To answer your question, you would adapt the instructions in the yeast experiment and measure the amount of carbon dioxide produced by yeast that had been exposed to varying amounts of x-rays. Instead of using different sugar sources as described in the project, you would use sugar and yeast exposed to different levels of x-rays.

Does this explanation help? Let me know if you have questions.


Donna Hardy

Dear acsci_researchers,

You might consider switching your project from X-rays to UV light. UV light and X-rays will have somewhat similar effects on microorganisms. Both will induce DNA mutations. UV lamps are cheaper, safer, and easier to work with than X-ray machines. For example, you could grow yeast in a Petri dish and then expose various parts to different intentness of UV light. You can do this by covering part of the Petri dish with cardboard (or anything impervious to UV light) and exposing the rest of the Petri dish to UV light. You can vary the intensity by exposing various parts of the Petri dish to varying lengths of exposure to the UV light. I did these exact experiments in grad school and they always worked very well.

I hope this helps.

-Dave