How to Extract DNA from a Strawberry in Your Kitchen
Here is a description of the procedure that we carried out in class along with notes for how you can modify the lab if you were to do it at home. You may also want to preview the links at the bottom of the page.
Do not attempt to eat or drink any of the materials or solutions.
Strawberry (can be fresh or you can thaw a frozen strawberry)
1000-mL beaker (you can substitute a large pitcher)
Test tube (you can substitute a small drinking glass)
50 mL dish soap
15 g NaCl (table salt)
70% isopropyl alcohol (rubbing alcohol; can be found in any pharmacy)*
*For best results, chill the rubbing alcohol before performing the experiment.
1. Prepare the DNA extraction buffer by mixing 950 mL water, 50 mL dish soap, and 15 g table salt. Since you probably do not have scientific measuring instruments in your kitchen, you may need to convert to non-metric units. If you have a measuring cup, 950 mL water is about 4 cups. If you have measuring spoons, 50 mL dish soap is about 3 1/2 tablespoons. You will need a large pitcher to put the solution in. You will probably want to make a much smaller portion. I would suggest: 9.5 mL (2 teaspoons) water and 0.5 mL (1/10 or 0.1 teaspoon) dish soap. If you do not have a way to measure out 15 g of salt (I used a very precise balance that you would not find out of a lab) you may just need to estimate (15 g is a 0.5 oz).
2. Place a strawberry in the Ziploc bag and smash it for a full minute or two, careful not to break the bag. Try to make the strawberry as liquidy as possible.
3. Add 10 mL (2 teaspoons) of the DNA extraction buffer to the bag. Mush the strawberry for another minute.
4. Place the coffee filter in a funnel over a test tube (or drinking glass). Pour the liquid strawberry into the coffee filter and let it filter into the test tube or glass.
5. Pour the chilled rubbing alcohol into the test tube or glass. I would suggest pouring an amount of alcohol that is roughly equal to the amount of strawberry in the test tube or glass). The DNA should start to precipitate (that is, separate out) of the solution.
6. You can use a toothpick to spool the DNA can collect it.
Links to other Pages on DNA Extraction
How to Extract DNA from Anything Living (from University of Utah Genetic Science Learning Center)
Extract DNA from a Strawberry Directions PDF file (from North Carolina State University)
Extract Your Own DNA (from NOVA Online by PBS)