Strawberry DNA Extraction Lab

On Friday (2/1/13), I performed a DNA Extraction laboratory experiment using strawberries. The materials I used were the following:

1. 1 strawberry
2. 5 mL liquid dishwashing detergent
3. 0.75 grams of salt
4. 45 mL water
5. Ice cold ethanol
6. Zip lock plastic bag
7. Filter paper
8. Funnel
9. Clear test tube

I will list each step below along with the reason for why each step was performed in the lab.

Step 1

First, I mixed 5 mL of dishwashing detergent, 0.75 grams of salt, and 45 mL of water to make the DNA extraction buffer.

Dishwashing detergent has the ability to break down the the membranes of a cell, releasing DNA in the process. Salt allows the DNA molecules to stick together and also removes excess proteins from the strawberry cells. Water was used mainly to allow for movement of the DNA in the solution.

The Crushed Strawberry with DNA Buffer

Step 2

Next, after creating the buffer, I cleaned the strawberry with water so that no unnecessary or unwanted materials were part of the experiment. Then, I placed both the cleaned strawberry and the DNA extraction buffer into a bag and crushed the strawberry using my hands. This breaks down the membranes of the strawberry and allows the DNA to come out of the cells.

Filtering out the excess materials from the strawberry

Step 3

I then placed a funnel in a test tube and covered the funnel in filter paper to remove excess materials from the mixture. Then, I poured the strawberry mixture into the funnel, and the liquid poured into the test tube through the filter.

Filtering the liquid from the strawberry mixture

The strawberry liquid with the DNA extraction buffer is shown below.

The strawberry liquid and DNA extraction buffer

Step 4 (Final Step)

I then placed ethanol into this test tube. I used ethanol because it separates the DNA strands from the strawberry liquid. The video below shows the separation of the DNA and the strawberry liquid.

The DNA of the strawberry is the stringy material located on the liquid (ethanol) above the red strawberry liquid.

Overall, this experiment was surprising to me in that anyone can extract DNA using simple materials such as dishwasher detergent, salt, water, and some strawberries. DNA plays a huge role in the lives of every living thing on Earth, and this experiment also allowed me to actually see DNA of a strawberry. This experiment shows that there exists so much more in nature than what meets the eye.

Sid