DNA Extraction from Wheat DNA Extraction from Wheat GermGerm

Compliments of the Salk Institute and the Southern CA Biotechnology

Center at Miramar College

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?

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

The Yellow Label is IsopropanolWhat is the Green Stuff?

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

Think!

HINT: Wheat Germ comes from plants but the Water is removed

What do you think is happening to the wheat

germ?

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.

Add Soap

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)

While the Wheat Germ is Heating Get a Tube Ready for Your DNA and Think

About What Will Happen NextLabel 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

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

Precipitate the DNA with AlcoholFill 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.

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.

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

Pick Up the DNA for Transfer into the Small Tube

Isolate the DNA into Your Small Tube

Place DNA in microfuge tube.

Observe color, quantity and texture

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

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?)