Science club today featured a local female microbiologist! She helped the kiddos extract DNA from their own saliva! It went a little like this…
Swish with clear colored Gatorade for 2 minutes (this was the longest 2 minutes EVER).
Place 5 ml of it in a test tube.
Add 2 ml of clear dish soap and rock back and forth to blend.
Then about 2 – 3 drops of pineapple juice and rock back and forth to blend.
Trickle a small amount of ice cold alcohol down the side of the test tube (91% isopropyl if possible).
DO NOT MIX!! Alcohol should float at the top.
Use a skewer to take out the layer that has formed between the alcohol and the rest. Twist the skewer gently to get the DNA to stick to it and pull it out gently.
It was amazing!!
Here are more detailed instructions: http://www.livescience.com/37252-dna-science-experiment.html