How do you stain cheek cells?

[biobuddy]

Hi, I'm doing a project about gel electrophoresis. The idea sort of came from this website. At the top of the page, it says that the scientist must stain the macromolecules to see them in the gel, but at the bottom instructions it says nothing about DNA, only food coloring dyes. I tried the experiment once, by taking some cheek cell samples and mixing them with food coloring. Then when I drop it into the gel and turn it on, nothing happens. The ends where the electrodes are start bubbling, but nothing moves. I think I'm staining them wrong. So my question is, how do you stain the cheek cell samples?

Thanks for reading.

[davidkallman]

Hi biobuddy,

If you submit "How do you stain cheek cells?" to answers.com, you'll get many resources. I haven't looked through them all, but
http://www.mos.org/sln/sem/staining.html
seems to have a procedure.
Please post again if you have any questions. Note, you may find good resources on the later pages of the output.

[adance]

Are you trying to run whole cheek cells on gel electrophoresis? I don't think that will work--cells are too big to go through the matrix. Gel electrophoresis is commonly used to separate DNA or proteins of different sizes. In order to have the DNA run through the gel, you have to chop it up with restriction enzymes--whole genomic DNA will just get stuck in the wells. You mention you have bubbles so it sounds like your electrophoresis is working, so that's good.

Staining whole cheek cells would probably be something you'd do to look at them in the microscope. Staining DNA in a gel involves different chemicals.

Can you tell us a little more about what you're trying to accomplish? Then we can provide more specific advice to get you to your goal.

[donnahardy2]

Hi Biobuddy,

Did you try using the food colors as samples? I read through the project, and the experiment listed uses the food dyes as samples. There is a discussion about DNA and protein, but the actual experiment suggested does not include instructions for doing electrophoresis on these biomolecules. In the experiment as described, you run your electrophoresis experiment with the various dyes to separate them into different components: https://www.sciencebuddies.org/science- ... p028.shtml

To do electrophoresis on the DNA in your cheek cell samples, you would need to solubilize the whole cell and use the restriction enzymes that Amber referred to on the sample. You would need agarose to make gels with a large porosity for DNA molecules, and a stain that would bind specifically to DNA. Ethidium bromide, which is toxic, is usually used, but there is a safer stain called fast blast available if you can find it. Here is a website that describes how to do electrophoresis of DNA samples:

http://a32.lehman.cuny.edu/molbio_course/agarose1.htm

The food dyes are water soluble colors, and they don't bind to DNA or to proteins. Cheek cells are several microns in diameter so would never be able to get into the pores of an electrophoresis gel. This is why your experiment didn't work well. However, the bubbles you saw indicated that a current was flowing through your electrophoresis apparatus. So, your project was successful, even if your experiment didn't work. Why don't you try separating the dyes in the food coloring and see if that works?

I hope that helps to explain things. Please let us know if you need any additional explanation. Gel electrophoresis is an excellent technique, and you can do a lot with it.

Good luck!

Donna Hardy

[dancingonli93]

Hi Biobuddy,

You may want to use iodine or methylene blue which your science teacher should have. If you are still unsure, your science teacher should know of a way to stain cheek cells.

[tashbaird]

Hey,
Try toluene blue. This stuff stains anything and we used to use it to stain microscope slides.