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Lana Hays


fresh onions
graduated cylinders (10ml and 100ml)
15-ml test tube
test tube rack or 250 ml beaker  
glass stirring rod
coffee filters
non-iodized salt
Adolph's natural meat tenderizer
Palmolive detergent
distilled water
ice cold 95% ethanol


Detergent/salt solution:
20 ml detergent
20 g non-iodized salt
180 ml distilled water

5% meat tenderizer solution:
5 g meat tenderizer
95 ml distilled water


  1. Cut an inch square out of the center of 3 medium onions. Chop and place in a blender.
  2. Add 100 ml of detergent/salt solution.
  3. Blend on high 30 sec-1 minute.
  4. Strain the mixture into a beaker using a strainer with a coffee filter.
  5. Add 20-30 ml meat tenderizer and stir to mix.
  6. Place 6 ml filtrate in a test tube.
  7. Pour 6 ml ice cold ethanol carefully down the side of the tube to form a layer.
  8. Let the mixture sit undisturbed 2-3 minutes until bubbling stops.
  9. The DNA will float in the alcohol. Swirl a glass stirring rod at the interface of the two layers to see the small threads of DNA.
Modified from: "Isolation of DNA from Onion" Ellen Averill

Onion | Wheat Germ | Lima Bean Bacteria | Thymus | Yeast | Data Sheet and Questions | Design Your Own DNA Extraction Protocol | Teacher Information | References

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