DNA Spooling Lab
- 20 ml chilled buffer solution.
- approximately 10 ml chilled ethanol.
- coffee stirrer.
- 25 ml graduated cylinder.
- (1) small plastic container.
- (1) beaker (100 or 150 ml).
- methylene blue stain.
- Place pieces of the onion in a blender with a little distilled water and pulse in short bursts.
- Place 10 ml of the onion mash into the beaker.
- Add 20 ml of chilled buffer.
- Stir vigorously for at least 2 minutes.
- Pour the mixture through filter paper and collect the liquid in the plastic container.
- Add an equal volume of chilled alcohol to the DNA / buffer solution. Tilt the container and allow the alcohol to dribble down the side. The alcohol is less dense and will float on top of the DNA / buffer.
- To spool the DNA, insert a wooden coffee stirrer through the alcohol in the DNA / buffer solution. Gently twirl the stick just below the boundary of the two layers. After a minute of twirling, slowly pull the stick up through the alcohol. The DNA (white precipitate) will adhere to the stick.
- You may add a small amount of blue food coloring to the plastic container to see any uncollected DNA.
In a clean glass, mix together the following:
- 4 ounces (120 ml) of water
- 1/4 teaspoon (1.5 gm) salt
- 1 teaspoon (5 gm) baking soda
- 1 teaspoon (5ml) of shampoo