Dramatic DNA!

15 Nov

Most high school biology textbooks contain a brief description of the history of DNA research.  Stduents read a little bit about Francis Crick, James Watson, Maurice Wilkins, and sometimes Rosalind Franklin as well.  Dramatize this for your students by showing clips from the film “Life Story”, starring Jeff Goldblum:

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5 Responses to “Dramatic DNA!”

  1. Stuart Farrimond November 24, 2010 at 1:56 PM #

    Students can also have fun doing this practical (doesn’t take long and it actually works!) where students can actually visualise DNA. Actually seeing the white-stringy DNA has quite a lasting effect: http://learn.genetics.utah.edu/content/labs/extraction/howto/

    • Excited Neuron November 27, 2010 at 4:18 PM #

      Stuart,

      I do a DNA extraction every year. The first two times I did it with strawberries, blueberries, and bananas. The bananas didn’t work too well, for those that are curious.

      However, what I’ve found works best (and keeps the students much more interested) is extracting DNA from the students themselves!

      It’s the same basic protocol as what you linked to. You need dishwashing soap, cold alcohol (though 95% ethanol seems to work better than rubbing alcohol), meat tenderizer, and Gatorade.

      You give the students a little bit of Gatorade in a disposable cup (try to use a light color of Gatorade, like the white or yellow) and have them swish it around in their mouths for 1 minute. Then they spit it back into the cup. The put a teeny amount of soap in the bottom of a test tube, fill the test tube halfway with their Gatorade mixture, then add a pinch of meat tenderizer. They need to put their hand or thumb over the test tube at this point and invert it a few times.

      Next, you’re supposed to wait about 10 minutes. During that time I discuss why we use all the different things we are using in the lab (like how meat tenderizer has proteases in it that get rid of the proteins that hold the DNA in its wound up shape, etc). After 10 minutes, you add about 2 cm of cold alcohol to the test tube, and voila!

      I also give the students a little centrifuge tube to put their DNA in so they can keep it.

      • Stuart Farrimond November 27, 2010 at 8:01 PM #

        Thanks, that’s awesome 🙂
        That sounds much better than the fruit/veg one. Not sure if we have Gatorade in the UK – I guess it’s like Lucozade?? I also found that meat tenderiser doesn’t seem to be sold in the UK either, I’ve used pineapple juice but I doubt this would work with cheek cells? Might have to ask the lab technician to do some hunting…

      • The Excited Neuron November 28, 2010 at 8:02 AM #

        I googled Lucozade, and it looks basically the same…they’re sports drinks. That’s really surprising that there is no meat tenderizer sold in the UK!

      • Stuart Farrimond November 28, 2010 at 2:30 PM #

        Thanks 🙂
        Yeah, from googling – I’ve found that you can get meat tenderiser online but most uk supermarkets don’t stock it… Maybe you guys have different quality or taste for meat??? 🙂

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