If you have a Cell Project on the front counter, please take it now (put on hallway table and take it after class). Materials: ISN

1. Define extraction in your own words. 2. How do you suppose we will extract DNA from strawberries and peas? 3. What are your predictions for how DNA will look?

DNA Extraction DNA is the genetic code-of life DNA is found in the chromosomes Chromosomes are found in the nucleus All eukaryotic cells have a nucleus All living organisms are made of cells

DNA Extraction - Steps Collect cells Burst cell membranes open - salt Dissolve lipid (fat) layer - soap Separate DNA from proteins and debris - salt Isolate concentrated DNA – 91% Isopropyl Alcohol (stored in freezer)

water Measure 10 ml of water

Take the green part off the strawberry

Add the strawberry, 10 ml. water, and 3 pinches of salt to the baggy.

“ Smoosh” the strawberry with your fingers

Use the stick to get a drop of soap

Add a drop of soap to the baggy

Gently rock the baggy back-and-forth (so you don’t make bubbles)

Put the coffee filter into the funnel

Slowly pour the strawberry juice into the filter

It takes time to filter through

Pour the juice into the smaller beaker or test tube

Tilt both containers when you pour the alcohol down the side

Pull the DNA out with the pipette

Drawing Conclusions 1. Why was it necessary to add salt to the mixture? 2. Why was it necessary to add soap to the mixture? 3. What did the DNA look like? 4. Explain how DNA is stored in the nucleus. 5. Explain what happened in the final step when you added the alcohol. 6. List two reasons why it is important for scientists to remove DNA from an organism.