Strawberry DNA Extraction Lab by C. Kohn, WUHS and Stacy Fritz, NAAE
Name: Hour Date:
Date Assignment is due: At end of hour Why late? Score: /10 Day of Week Date If your project was late, describe why
Materials

measuring cup measuring spoons ice-cold rubbing alcohol
1/2 teaspoon salt 1/3 cup water 1 tbsp Dawn dishwashing detergent

cheesecloth Re-closable plastic sandwich bags test tube (or small glass jar)

3 strawberries (green tops removed) cup bamboo kabob skewer or Q-tip

Directions:
1. Mix the salt, water, and Dawn detergent in a glass or small bowl. Set the mixture aside. This is your extraction liquid.
2. Line the funnel with the cheesecloth, and put the funnel’s tube into the glass.
3. Put the strawberries in the plastic bag and push out all the extra air. Seal it tightly.
4. With your fingers, squeeze and smash the strawberry mixture for 2 minutes.
5. Add 3 tablespoons of the extraction liquid you made in Step 2 to the strawberries in the bag. Push out all the extra air and reseal the bag.
6. Squeeze the strawberry mixture with your fingers for 1 minute.
7. Put cheesecloth over the funnel and place the funnel in your test tube. Pour the strawberry mixture from the bag into the funnel. Let it drip into the test tube until there is no liquid left in the funnel.
8. Throw away the cheesecloth and the strawberry pulp inside. Pour out the contents of the test tube so it is 1/4 full.
9. Tilt the test tube or jar and very slowly pour the cold rubbing alcohol down the side. The alcohol should form a layer on top of the strawberry liquid. (Don’t let the alcohol and strawberry liquid mix. The DNA collects between the two layers!). Slowly add enough alcohol so that you have equal parts of both liquids.
10. Dip the bamboo skewer