Ever wish you could see the strands of genetic material that make you...you? Well, you can! And the the best part is, that all you need are some common household items!
Note: It's best to do this experiment in the morning before you eat breakfast. You want to see your own DNA, not the scraps of food that got stuck in your teeth!
Ingredients:
bottled water, clear dish soap, food coloring, table salt, 70% isopropyl alcohol, 3 clear cups, you (and a friend or family member)
Procedure: (Written & Video)
Step 1: Mix 500 ml drinking water with 1 tbsp salt
Step 2: Stir until salt is dissolved. Then transfer 3 tbsp of salt water into a clear cup.
Step 3: Gargle the salt water for 1 minute.
Step 4: Spit the water back into the cup. Now your cheek cells are suspended in the salt water.
Step 5: Gently stir the salt water with one drop of soap. (Avoid bubbles as much as possible).
Note: Soap breaks down the cell membranes, releasing the DNA.
Step 6: In a separate cup, mix 100 ml isopropyl alcohol and 3 drops of food coloring.
Step 7: Tilt the salt water cup and gently pour the alcohol so that it forms a layer on top (about 2 cm thick).
Step 8: Wait about 2.5 minutes. You should see white clumps and strings forming. That's your DNA!
Did you see your DNA? Did it look like you thought it would? Probably not. Most people picture DNA as a sort of "twisted ladder" shape because that is the model we are taught about, but DNA is actually clumped very tightly inside our cells. What you saw was large clumps of your DNA, not individual strands like we see in our textbooks. Watch the video below for a more clear explanation of why you didn't get to see the "twisted ladder" shape.