Isolating DNA from Veggies

Presenters

Olga Kochan
Cheryl Hackworth

DNA Extraction Protocol

1. Pick out your veggie

You will want to pick out softer vegetables with a lot of pulp because they are easier to grind and break open the cells. We prefer tomatoes, bananas, kiwis, or mangos.

2. Cut up the tomato

Cut the tomato into pieces small enough to fit in the bowl.

3. Add extraction buffer and soap

Add about 2 tablespoons of extraction buffer and a couple of drops of liquid soap. The extraction buffer contains salts that mimic the environment inside the cell, allowing the cell's contents to spill out. The liquid soap breaks open the membranes surrounding the cell and the nucleus, where the DNA is. These membranes are made of greasy fats and, just like liquid soap cuts through grease on your dishes, it breaks open the fats that surround the cell and the nucleus and the DNA spills out. But first we must break open the cell wall that holds the cell in place.

4. Grind the tomato

Grinding for a minute breaks open the cell wall so the liquid soap can break open the cell membranes and the nuclear membrane.

5. Strain the slurry

This removes all the cells you have not opened yet.

6. Add water and ethanol

Pour half a tablespoon of the slurry into a clear glass or tube and add an equal amount of water. Carefully add 4 tablespoons of cold ethanol.

The ethanol precipitates the DNA from solution.

7. Swirl the two solutions to see DNA

DNA is the snotty looking substance. A lot of this is water, but it also contains a good deal of DNA.

8. Congratulations, You are a genetic engineer!

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Last updated: February 14, 2006