DNA Extraction

I’m in the middle of the Cell Unit now. We’ve already established the structure and function of the cell membrane and are now working on the structure and function of the nucleus. The Cheek Cell Lab went off without a hitch and the post-lab discussion revealed that my kids remembered that the nucleus was the “control center” of the cell and it contained DNA. One class remembered that the letters for DNA were A,T,C,G. At this point we transitioned to the DNAi.org Activity about DNA structure. Next year I think I will add in a DNA Extraction Lab in between the Cheek Cell Lab and the DNAi.org Activity. I find that students “get” DNA better after they have seen actual DNA. In the past I’ve used a strawberry DNA Extraction from the Exploring Life Textbook by Campbell, Williamson et. al. One of the other teachers in the department does an extraction using cheek cells and a “mouthwash” solution. I think I’ll try to combine these two labs together. I really like the idea of extracting DNA from cheek cells after the kids observed their own cheek cells under the microscope. The kids will get a macro view of DNA from the abstraction and we can then transition to a micro view of DNA with the DNAi.org Activity. Later this Spring or in the Summer I’ll purchase the DNA model kits depending on when the district frees up some money.

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About ryanwoodside

I help students learn science. I teach at Mt. Ararat High School in Mid-Coast Maine.
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4 Responses to DNA Extraction

  1. Rebecca Stanley says:

    There are many activities in Biology that I feel connected to and thus tend to hang about beyond their usefulness; DNA extraction was one of them. On one hand, it’s really cool and kids have fun doing it. On the other hand, it doesn’t really move a student’s conceptual understanding of how cells work and it doesn’t illuminate any secrets about the structure or function of DNA.

    When I encounter these activities I ask myself a series of questions: what is the model students are constructing? How does this activity aid students in constructing the model? What will students do and what questions will they be answering? Are there opportunities for students to answer the questions in multiple ways or is there a set procedure to follow with a predetermined ending?

    In the end, I found DNA extraction was not worth the time. Perhaps you come to a different conclusion; I would love to hear about how you make it more meaningful!

    • Anita Schuchardt says:

      Rebecca, I was looking at the original post to compose a reply on the BIOMOD listserv when I found your response. You said part of what I wanted to say – much better than I could manage to say it. I particularly like the set of questions and I think they could be more generally helpful. Would you or Ryan mind posting your response on the BIOMOD listserv to try and open up a more general discussion?

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