Science Buddies: "Ask an Expert"

Hi,

i was wondering how you would measure the amount of alive cells after a stress experiment. Is there any efficient and economical way to do this?

Thanks!

Hi,

I am interested in conducting an experiment regarding a possible way to treat cancer. I was wondering what would be the most appropriate simulate tumor cells.

Thanks.

Hi kevinhahahaha,

Cancer is a very interesting topic. The way viable cells are usually counted is using a vital dye. One such dye is called Trypan Blue. Live cells actively exclude the trypan blue dye, while dead cells cannot. In this way only dead cells appear blue. The cells can be counted using a Neubauer hemocytometer and a microscope. Here are some pages that describe this process:

http://www.ruf.rice.edu/~bioslabs/metho ... nting.html

http://www.che.udel.edu/mranton/pdf/pro ... _cells.pdf

As for your second question I will need more details. What kind of tumor cells are you going to use. Most cancer cell lines that have been studied have specific conditions that stimulate them. Let me know what kind of cells you are using.

-Kierstyn

Hi Kierstyn,

Thanks for your help! Regarding the second question, I do not know which tumor cells I am using for I am not sure if I can gain access to tumor cell lines. In the event that I do not have access to tumor cell, I was wondering how/which organism I should use to test the toxicity of the drug.

Thanks,

Kevin

Hi kevinhahahaha,

Will you be able to get access to non-cancer cell lines? If so you would want to pick a similar cell. Say a human hepatocyte (liver cell) line to study liver cancer. If getting any kind of cell line is not an option you will want to stick with Eukaryotic cells. You could use yeast which you can get from the grocery store. It won't make sense to use and prokaryotes (bacteria) since their physiology and metabolism is drastically different.

There are many different assays that you can use to measure drug toxicity. But the general idea is to take cells and incubate them with a few different concentrations of the drug. After a set amount of time you measure the viability of the cells and plot the data. From this kind of assay you can determine the highest dose of the drug that does not affect cell viability. You could use trypan blue to measure the number of dead vs. live cells. If you use yeast you can measure colony forming units (CFU) on an agar plate to measure viability. Here is a protocol for measuring yeast CFU.

http://biology.clc.uc.edu/fankhauser/La ... _Count.htm

Let me know if any of this sounds like a good idea.

Kierstyn

Hi Kierstyn,

Thanks for your help! I will start from here right away.

Thanks,

Kevin