This document provides instructions for extracting DNA from onions. It lists the necessary materials which include an onion, a meat tenderizer and dishwashing liquid solution, ethanol, test tubes, beakers, a blender, and other common lab equipment. The procedure has students working in teams to chop an onion, soak it in a heated meat tenderizer solution, blend the mixture, filter it using cheesecloth, and add ethanol to precipitate and view the extracted DNA. The experiment is designed to be a simple kitchen chemistry demonstration that can extract visible DNA in under an hour.

1. DNA EXTRACTION FROM ONION
Material
 an onion;
 100 mL of a solution of meat tenderizer (0.05 g / mL water) and dishwashing liquid (0.01
mL / mL water);
 50 mL 95 % ethanol kept in the freezer or on ice;
 ice bath;
 cheesecloth;
 glass stirring rod;
 five (5) test tubes;
 250, 500 and 1000 mL beakers;
 blender;
 scale;
 water bath at 60º C;
 stopwatch.
Steps of the experiment
Working in teams of four (4), the students must extract DNA from an onion. This activity takes
fifty (50) minutes and only requires kitchen products and laboratory glassware.
The experiment
1. Chop the onion.
2. Pour the meat tenderizer solution (100 ml) into a 250 mL beaker and heat it to 60ºC in a
water bath.
3. Add 50 g of chopped onion to the meat tenderizer solution. Stir and let sit for 15 min. at
60ºC.
4. Remove the beaker from the water bath and immediately place it on ice for five minutes.
5. Pour the mixture into a blender.
a) Blend at low speed for 45 seconds and stop.
b) Blend at high speed for 30 seconds and stop.
6. Pour the mixture onto a piece of cheesecloth folded in four and draped over a 500 ml
beaker that is already on ice.
7. Gently squeeze off filtrate.
8. Pour about 5 ml of the filtrate into each of the individual test tubes that are already on ice.
Place the test-tubes in such a way that they rest at an angle.
9. Pour approximately10 ml of ice cold 95% ethanol down the wall of the test-tube.