1. DNA Extraction from Wheat Germ
Compliments of the Salk Institute and the Southern CA Biotechnology Center at Miramar College

2. Teacher - Materials Required
Palmolive soap –clear or lightest one
Isopropyl alcohol (cold and kept on ice… won’t work if it has not been in the freezer)
Wheat germ (buy in bulk at Sprouts/Trader’s Joes)
Plastic disposable pipettes (2 – one for soap one for alcohol)
Containers to keep both solutions (beaker, cups,etc.)
Inoculation loop (1)
Warm water bath (65 C)
Microcentrifuge tube (2)

3. In This Lab You Will Use Plant Cells found in Wheat Germ
You will need to break open the Cells to get the DNA
How many layers do you need to go through to get to the nucleus?

4. Your Lab Set Up Should Look Like This- Find the Wheat Germ

5. The Yellow Label is Isopropanol What is the Green Stuff?

6. Get your Wheat Germ (Plant Cells)
Add a pinch of wheat germ to the water in the red capped tube
Gently stir the contents for 1 minute with a wooden stick

7. What do you think is happening to the wheat germ?
HINT: Wheat Germ comes from plants but the Water is removed

8. Break Open the Cells
Using transfer pipet add 3 ml of 20% Palmolive soap to the tube with water and wheat germ.
Remember to Leave the pipet in the soap.

9. Add Soap

10. Heat to Release DNA
Cap the tube with the wheat germ and gently swirl to mix.
Remember to loosen the cap slightly before placing tube in hot water.
Heat for 5 minutes. (Heating at 65 recommended)

11. While the Wheat Germ is Heating Get a Tube Ready for Your DNA and Think About What Will Happen Next
Label a small tube containing 10 drops (1/2 ml of isopropyl alcohol (rubbing alcohol!)
The next slide will prepare you for what will happen next

12. The Next Step is to Extract the DNA
To Do this you need to form two layers in the tube like this
Identify the 2 layers in the tube
Where is the wheat germ?
Now Precipitate Your DNA

13. Precipitate the DNA with Alcohol
Fill a transfer pipet with 3ml of alcohol.
Bring your tube with wheat germ back to table and add 3 ml of alcohol gently to down the side of the tube.
DON’T MIX THE LAYERS!!!
Remember to leave pipet in alcohol.

14. DNA is Hydrophobic and Moves into the Alcohol Layer
Watch the DNA rise out of the green soap layer and into the alcohol layer
After waiting a few minutes to allow the DNA to precipitate remove DNA using an inoculation loop.

15. DNA forms at Alcohol-Soap Interface- Spool DNA Onto Loop

16. Pick Up the DNA for Transfer into the Small Tube

17. Isolate the DNA into Your Small Tube
Place DNA in microfuge tube.
Observe color, quantity and texture

18. Clean Up !
Recap the 50 ml conical tube and leave in the foam rack. Your teacher will send this tube to be washed and recycled!
Leave the rest for the next class.
You may keep your tube of DNA

19. Observe Was the isolated DNA very Stringy? What color is the DNA?
Do you think the DNA from the cells in your body will look the same? (why or why not?)