OK, it is about time that I add some science to this blog largely devoted to all things arts & crafts (I did put it in my blog title...). I think that elementary school is a great time to teach kids about DNA and some elementary principles of genetics! While helping my Girl Scout Juniors earn their "Detective" badge, I threw in some additional items to earn an additional "Make your own" Science badge. As everyone knows, above is a depiction of DNA- a double stranded helical molecule encoding information to encode all sorts of proteins. I could go on and on about how fascinating it is: but I won't so as to keep this post within reasonable length!
I had the girls isolate their OWN DNA by themselves (no need to be in a lab, but parental supervision is required) and they had a blast.
First, the following ingredients are required: few drops of dishwasher soap, 6-8 milliliters of COLD isopropyl ethanol (70% is fine), pinch of salt, container with a cap and saliva (DNA source).
Have each child spit into the container until they have between 1 milliliter and 2 milliliters of saliva(the girls thought this was gross at first, but then hilarious). Next add a few drops of dishwasher soap (or any kind of soap)- this breaks open cells and releases the DNA. Gently tap the container to mix the saliva and the soap. Add a pinch of salt to aggregate the DNA that is in the solution (you won't be able to see it yet). Finally add 6-8 milliliters of COLD isopropyl ethanol to allow the DNA to "come out" or precipitate out of solution by gentle inversion of the container (will have to do this several times) and you'll be able to see it! Yup, your DNA is that stringy slimy white clump! All the girls brought their DNA home to show their parents- they were pretty proud of themselves!
To add to the fun you can set up a fictional mystery. I explained that when you add certain enzymes that can cut up DNA (restriction enzymes), that each person will have a unique DNA fingerprint when run on an electrophoresis gel (don't worry about this part- you have to run this in a lab). You can set up a fictional mystery and use DNA fingerprinting to figure out the thief, etc. My 9-10 year old girls were easily able to solve the mystery, once I explained what to look for on the electrophoresis gel (distinctive pattern).
My girls definitely thought that DNA was fun!
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