Materials Needed:
Fresh strawberries (2-3)
Ziplock bag
2 Clear plastic cups
Water
Salt (1/4 teaspoon)
Dishwashing detergent (1/4 teaspoon)
Coffee filter or cheesecloth
Isopropyl alcohol (chilled in the freezer)
Tweezers
Step 1: Prepare the Strawberries
Gently rinse the strawberries under cold water to remove any dirt or debris. Remove the green leafy tops and cut the strawberries into small pieces. Place the strawberry pieces into a ziplock bag and seal it, ensuring there is no air trapped inside.
Step 2: Mash the Strawberries
Using your hands, gently mash and squeeze the strawberry pieces inside the sealed bag. The goal is to break down the cell walls and release the DNA. Continue mashing for about 2-3 minutes until the strawberries are thoroughly mashed.
Step 3: Create the Extraction Mixture
In a plastic cup, mix 1/4 teaspoon of salt, 1/4 teaspoon of dishwashing detergent, and 50 mL of water. Stir the mixture gently to dissolve the salt and detergent.
Step 4: Add the Mashed Strawberries
Open the ziplock bag and pour the mashed strawberries into the extraction mixture. Stir the contents gently for about 5 minutes to ensure thorough mixing.
Step 5: Filter the Mixture
Place a coffee filter or cheesecloth over another cup or beaker. Carefully pour the strawberry mixture through the filter, allowing the liquid to pass through while trapping the pulp and debris. Squeeze the filter to extract as much liquid as possible.
Step 6: Precipitate the DNA
Pour the filtered strawberry liquid into a test tube or small glass container, filling it about one-third full. Slowly add the chilled isopropyl alcohol to the cup, pouring it down the side. You should see a clear layer of liquid form at the top with a cloudy white layer below. This white layer contains the extracted DNA.
Step 7: Collect the DNA
Take a pair of tweezers and gently insert them into the cloudy white layer of DNA where you can see the stringy DNA strands forming. Carefully pinch with your tweezers and lift the stringy material to collect the DNA.
Congratulations! You have successfully extracted DNA from strawberries. You can observe and marvel at the extracted DNA or even store it in a small container for further exploration or experimentation.
