Home DNA extraction
How can you isolate DNA in your own kitchen?
Conduct this experiment only under adult supervision.
Reagents and equipment
- 200 mL isopropyl alcohol;
- 1 tbsp table salt;
- 10 drops of liquid soap containing sodium dodecyl sulfate;
- 100 mL hot water;
- 100 mL cold water;
- shot glass;
- deep dish.
Prepare a precipitating solution: combine 1 tbsp table salt and 10 drops of liquid soap containing sodium dodecyl sulfate in a glass. Add 100 mL hot water. Stir well.
Place a peeled banana in a glass. Add 5 tablespoons of precipitating solution and 100 mL cold water. Blend the mixture thoroughly.
Filter the puree through several layers of gauze. Carefully add 200 mL ice-cold isopropyl alcohol by pouring the liquid down the side of the glass. Observe the formation of a white mass in the alcohol layer.
DNA is a molecule with a complex structure that stores and passes the genetic information of every living organism on Earth from generation to generation. This simple method for DNA extraction is based on the following principles: the liquid soap contains surfactants, which help destroy the cell membranes and nuclei, while sodium ions from the salt bind to the phosphate groups of the DNA molecules, helping isolate the DNA from the solution. Adding cold isopropyl alcohol reduces the resulting DNA and sodium compound solubility in water. You can also use this method to isolate the DNA of strawberries, peaches, and tomatoes.