6 year old Cutie Pie has had his eye on this DNA experiment from our 50 Science Things to make and do book ever since we first got it. Unfortunately, whenever we sat down to do an experiment in the past this was just never picked! So the Friday Cutie Pie and Sweet Pea had off for Superintendents conference I made sure to pull this out. Little did I know how perfectly it would fit into our weekend! (But, if you read We are Unique then you already do!)
(This experiment was taken from 50 Science Things to Make and Do, by Usborne Activities. We really love the experiments in this book!)
First, make sure an adult is helping you. Then either you or the adult can finely chop up your onion with a sharp knife and place the pieces in a bowl.
Pour in just enough dishwashing liquid to coat the onion pieces and stir.
Add 1/2 teaspoon of salt and carefully pour in two tablespoons of water trying not to make any foamy bubbles. Stir again, trying not to make any bubbles. Let this mixture sit still for 10 minutes.
Stir the mixture gently again, then place it in a sieve over a bowl. Pour the liquid that escaped into a glass jar, removing any foam with a spoon.
Carefully trickle rubbing alcohol into the jar, letting it run down the side of the jar so no more bubbles are made. This will make a second layer of liquid in the jar. Do not stir!
Set your timer for 20 minutes this time. At the end of 20 minutes or so you should see a white, stringy substance in the top layer. This is the onion’s DNA!
What’s going on? DNA does not break down in the dishwashing liquid and salt like the rest of the onion does. DNA doesn’t dissolve in alcohol, so it appears as the solid white strings!
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