October 17, 2012
Extracting DNA from Strawberries
Problem/Question: Successfully extract the DNA from strawberries. Theory/Hypothesis: N/A
Variables: Independent – strawberries
Dependant – the DNA
Controlled – 450 ml of water, 50 ml of soap, 1 tsp of salt, 5 ml isopropyl alcohol Apparatus and Materials: N/A
Procedure and Control of Variables: N/A
Data Collected: See attached paper.
Data Processing and Presentation: In this experiment we extracted DNA from two strawberries. First, we made a solution consisting of 450 ml of water, 50 ml of dish soap, and 1 tablespoon of salt and mixed it in a beaker. The solution was mostly clear, but a little frothy and yellow from the soap. Then, in a plastic bag we mashed two of our strawberries with 40 ml of our solution. It became a pink, foamy puree with a few chunks of strawberry. Next, we filtered our strawberry mix into a test tube. It filtered very slowly because our mixture was so thick. Never the less, we got enough to continue on. We finally measured out 5 ml of isopropyl alcohol and added it to our test tube. The end result was pretty fascinating. The red strawberry mixture mostly stayed under the clear isopropyl alcohol in two layers. Then, little translucent strands, the DNA, floated up into the alcohol from the strawberry mix. There it froze in a clump. Conclusion and Evaluation: This was a very successful experiment for my group. We extracted a lot of DNA from the strawberries. I found it fascinating how the isopropyl alcohol separated from the strawberry mixture and the DNA floated u p into it. However, I’m not exactly clear on why the DNA did that. I think it would be fun to try this experiment on other types of fruit and see if it was possible to collect their DNA as well. Overall, this was an exciting experiment and I now have a more realistic idea of what plant DNA looks like.