Fruitful DNA Extraction

Wed, 06/10/2009 - 9:19am
By: The Citizen

What do strawberries and bananas have in common with Whitewater Middle students? The answer is DNA. As it turns out, the genetic material of the fruits is very similar to that of humans.

This was just one fascinating fact that approximately 290 seventh graders learned as they participated in a DNA extraction lab conducted by graduate students from the Georgia Plant Scholars Program of the University of Georgia’s (UGA) Plant Pathology Department.

Using regular household items such as coffee filters, salt, dishwashing liquid, water and rubbing alcohol, students learned how to extract DNA from bananas and strawberries. What once took months to complete in a laboratory, took the students less than an hour.

Here is how the process works. The fruit is mashed to breakdown its cell walls and then mixed with salt and dish soap. The soap dissolves the fatty part of the cell wall and the nuclear membrane while the salt breaks up the protein chains that bind around the nucleic acids. This chemical reaction allows liquid containing DNA to pass through the coffee filter and into a container. When rubbing alcohol is added to the container, fine white strands of DNA appear. The DNA forms whitish stringy material that can be spooled onto a toothpick.

UGA’s DNA extraction labs are in high demand around the state. It took science teacher Daniece Post two years to get one at Whitewater using some connections she made at a conference.

“I participated in a UGA workshop in Athens and met Kisha Shelton, the program coordinator of Georgia Plant Science Scholars. We realized we had worked with some of the same professors during our internships and I asked if she would be willing to come to Fayetteville to do a lab. We have worked for two years arranging our schedules for the visit,” says Post.

The lab experiment was used to reinforce the Life Science Georgia Performance Standards that includes levels of cellular organization, cell structure and function, and the role of genes and chromosomes, as well as introduce students to careers in areas not commonly associated with science.
Michaela Phillips (left) and Rocio Obregon prepare to extract DNA from a banana.

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