Help your little ones learn about cells and DNA by extracting DNA from a strawberry. Science experiments with kids are a great way to keep you little ones busy and learning at the same time. Plus, they’ll love diving in and playing mad scientist for the day. Strawberries are soft, with huge genomes, making them easy to extract DNA from and a good way to see a large sample. Here’s how to dig the DNA from the strawberries in your refrigerator:
Step 1: Remove the stems and leaves from a strawberry.
Step 2: Smash the strawberry in a sealed Ziplock for a couple minutes. Squishing the strawberry to goo releases the DNA.
Step 3: Mix two teaspoons of dish detergent with one teaspoon of salt and ½ cup of water in a plastic cup. This is your magic DNA extraction juice.
Step 4: Dump two teaspoons of DNA extraction juice into the bag with the mushed up strawberry to help break open the cells.
Step 5: Mash for another minute, but let the parents or older kids take on this task because they have to be gentle as to avoid too many bubbles.
Step 6: Place a coffee filter on top of another plastic cup.
Step 7: Pour the combined strawberry mush and DNA extraction juice into the filter, allowing the juices to filter through and into the cup. Squeeze the filter so the remaining juices drip into the cup.
Step 8: Pour a glass of chilled rubbing alcohol that contains the same amount as your strawberry concoction.
Step 9: Pour the cold rubbing alcohol down the side of the cup, being very careful not to mix or stir the two liquids together. This brings the DNA away from the other stuff in the cells.
Step 10: Watch as the DNA surfaces. It will form a cloudy, white layer on top of the liquid.
Step 11: Use a plastic or wooden kitchen utensil to pull the DNA away from the rest of the liquid.
Thanks to the NIH for this experiment: http://www.genome.gov/pages/education/modules/strawberryextractioninstructions.pdf
-Photo courtesy of antpkr/freedigitalphotos.net