In this do-it-yourself science experiment, my 6 year old daughter, Samatha, demonstrates
how to extract one's own DNA at home using just few common household items.
Little bit about DNA:
Cells are considered as the building blocks of all living things. The human body is composed of around 37 trillion cells. Each cell has nucleus and other major parts like cytoplasm, mitochondria, plasma membrane etc.
In a nucleus, the DNA molecule is packaged into thread-like structures called chromosomes. Each chromosome is made up of DNA .
DNA (deoxyribonucleic acid) is the hereditary material in almost all living organisms. DNA contains the instructions needed for an organism to develop, survive and reproduce. Most DNA is located in the nucleus.
More about DNA, please see this link: http://ghr.nlm.nih.gov/handbook/basics/cell
Step 1: We Need
1. 500 ml water
2. 91% Isopropyl Alcohol (rubbing alcohol)
3. Dishwashing liquid
4. Food coloring (dark colors recommended)
5. 3 clear plastic cups
Step 2: Add One Tablespoon of Slat to Drinking Water
1. Pour 500ml water in a plastic cup
2. Add one tablespoon of salt to the water
3. Stir until the salt is dissolved completely
Step 3: Gargle the Salt Water
1. Transfer 2 tablespoons of salt water in a clear plastic cup
2. Vigorously gargle salt water for a minute
3. Spit salt water back into the same cup
When you gargle the salt water, it will collect some of your cheek cells. Now your cheek cells are in the cup.
Step 4: Add Clear Diashwashing Soap
Now slowly add 1ml of clear dishwashing soap to the salt water you just spit out
The dishwashing soap will break open cheek cells and their nuclei walls
and this causes the DNA to be released into the salt water.
Step 5: Mix Isopropyl Alcohol and 3 Drops of Food Coloring
1. Pour 100 ml isopropyl alchol in a separate clear plastic cup
2. Add 3 drops of food coloring, mix them well
Step 6: Pour Alcohol in the Salt Water Cup
1. Tilt the salt water cup and carefully pour alcohol such a way that it makes a layer on top of the salt water.
2. Wait for 4 minutes
The DNA is insoluble in isopropyl alcohol and it promotes the clustering of the DNA, making them visible.
Step 7: Results: Now We Can See DNA
After the procedure is done, we can see filaments of DNA on the top layer of the solution and after some time we can see white clusters of DNA at the bottom of the cup.