Get ready to weigh out the sand and onion with a medium or large weighing boat.

Slice up about 20 grams of yellow onion.

And about 20 grams of acid-washed sand.

Add chopped onions and sand to a mortar and pestle that has been kept on ice.

Grind up the onion and sand vigorously to break up the cells of the onion. It should be a mushy paste.

Weigh out 10 grams of NaCl.

And 10 ml of simple liquid dishwashing liquid.

Dissolve the salt and detergent in 100 mL of water. Use a hot plate to warm it up. Add 30 mL of the solution to a beaker with your onion mush. Stir for 5 minutes at 60C.

Use cheesecloth to strain out the solids from the liquid.

Slowly pour absolute ethanol down the side of the beaker so it forms a layer on top of your cell extract solution. DNA will precipitate at the interface.

Use a glass stir rod to spool out the DNA from solution. Turn the rod at the interface, but don't stir and mix the aqueous and alcoholic parts.

Transfer the DNA to a test tube containing 95% ethanol.