In this lab, participants will isolate DNA from strawberries or bananas using common household items. To keep strands of DNA intact, handle everything gently.
Supplies
- Two strawberries/ one banana
- 2 plastic cups
- water
- shampoo
- non-iodized salt
- coffee filters
- 70% Ethanol
- plastic gloves
- wooden sticks
Steps
- Put on one glove and squish about 1/2 a banana or two strawberries into one of the plastic cups. Squeeze the banana and strawberries until they are the consistency of a smoothie (small chunks are okay).
- Add 2 large squirts of shampoo and mix. Try to avoid getting too many bubbles by mixing gently.
- Add about a teaspoon of salt. Mix gently.
- Add an equal volume of water (it doesn't have to be exact).
- Strain about 1/2 of the banana mixture and all of the strawberry mixture gently through the coffee filter into the second plastic cup. Have one partner hold the coffee filter while the other partner pours the mixture in the center of the coffee filter. Allow the liquid to drip through. You may gently squeeze the coffee filter to get more liquid out.
- Add an equal volume of cold 70% ethanol to the liquid by pouring the ethanol down the side of the cup. Gently, swirl the cup. You should see the strings of DNA form and float to the top. Use the wooden stick to twirl the DNA around and pick it up out of the liquid.
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