How to Extract DNA (Deoxyribonucleic Acid) from Strawberries
The following was written by 7th grader, Ian Bollmann
On Friday, we extracted DNA from strawberries. We did this in groups of 3. The first step was putting the strawberries in a bag, and mashing them into pieces. The second step was mixing together 2 teaspoons of detergent, 1 teaspoon of salt, and ½ cup of water. The third step was adding the 2 teaspoons of the DNA extraction liquid (lysis solution) into the bag with the strawberries. This would further break open the cells, breaking down the cell membrane. The fourth step was to reseal the bag and gentle mash another minute. The fifth step was to place a coffee filter inside the plastic cup, open the bag and pour the strawberry liquid into the filter. Next, pour down an equal amount of cold rubbing alcohol to pull the DNA out of solution. Within a few seconds, watch for the development of a white cloudy substance (DNA) Finally, tilt the cup and pick up the DNA using a plastic coffee stirrer or wooden stick. Strawberries have a lot of DNA, so it was easy to see with your naked eye.
Each step is necessary and must be completed precisely for success due to the complex organization of DNA in cells. Strawberries are octoploid, meaning that they have eight copies of each type of chromosome. Strawberries yield more DNA than any other fruit. Students observed first hand that DNA is in the food that they eat.