Science Buddies: "Ask an Expert"

Hi,

I'm doing a project for gel electrophoresis, but I don't know how to collect
DNA. Could I just collect cheek cells? And one more question, after I collect the
Dna, how do I stain it?

Thanks very much,
Biobuddy

Hello biobuddy-sounds like an interesting project. Yes, cheek swabs are are good source for the DNA. Have you read the Science Buddies section on DNA testing?
I'm not sure about the gel-staining-hopefully one of the other experts will have some ideas for you.

dear biobuddy,

I have done gel electrophoresis in the past and I would suggest that you contact a local college or university or scientific lab because different labs have different techniques to perform electrophoresis. Also, the staining may differ between different types of cells. If you contact some scientists at a college or university I'm sure they will answer your questions. Also, some of the equipment and chemicals needed to perform gel electrophoresis may be expensive and are dangerous, so contacting and being supervised by a scientist at a college or university is a good idea.

good luck,
scienceexpert123

Hi biobuddy,

If your teacher has the equipment, it would also be possible to do this in a high school lab, I think. Do the biology teachers in your school do any experiments with gel electrophoresis?--it's a pretty standard technique. You'll need a gel tank and a number of reagents. Check out http://www.carolina.com/p2p/endecaSearc ... Search.y=0

There are standard protocols to get DNA from cheek swabs. Here's one example of a kit you can buy that supplies everything you need: http://www1.qiagen.com/Products/Genomic ... .aspx?pf=1
Qiagen kits are commonly used in molecular biology labs.

Keep in mind you don't want to just run genomic DNA in the gel--it will simply clog up the wells and won't go anywhere. You'll need to cut with restriction enzymes or otherwise treat it, depending on what you plan for your experimental question.

Here are some electrophoresis protocols to get you started: http://www.protocol-online.org/prot/Mol ... ophoresis/

As another expert mentioned, the standard DNA stain, ethidium bromide, is toxic. A safer alternative is called SYBR Green. You can order this and other reagents here: http://www.sigmaaldrich.com/life-scienc ... tains.html

Then, you'll need the capability to light up the stain and take a picture.

As you can see, it could get a bit expensive, depending on what kind of equipment you already have access to. Also, if you'll be working with human subjects make sure that's OK with the science fair regulations.

hope this helps, good luck!

Biotium's product GelRed and GelGreen is another safe alternative DNA stain to replace ethidum bromide. You may read more about the DNA stain technology here: http://biotium.com/technology/gelred-ge ... el-stains/

The entire DNA stain product catalog can be found here : http://biotium.com/product-category/pro ... -products/

The protocol found on methodbook is a good one for gel electrophoresis : http://www.methodbook.net/dna/agarogel.html