DNA Extraction: Strawberry
Name:___________________________
Background: The long, thick fibers of DNA store the information for the functioning of the
chemistry of life. DNA is present in EVERY CELL of plants and animals. The DNA found in
strawberry cells can be extracted using common, everyday materials. We will use an extraction
buffer containing salt, to break up protein chains that bind around the nucleic acids, and dish
soap to dissolve the lipid (fat) part of the strawberry cell wall and nuclear membrane. This
extraction buffer will help provide us access to the DNA inside the cells
Pre-Lab Questions:
1) What do you think the DNA will look like? ____________________________________
2) Where is DNA found? (be specific)___________________________________________
Materials
Ziploc bag
1 strawberry
15 mL DNA extraction buffer (soapy, salty
water)
Coffee filter
Funnel
50 mL vial or test tube
Popsicle stick
20 mL rubbing alcohol
Procedure:
1) Place on strawberry in a Ziploc bag. Close the bag.
2) Grind up the strawberry using your fist and fingers for about 2 minutes or until your
berry is liquefied. Careful not to break the bag.
3) Add the provided 15 mL of extraction buffer (salt and soap solution) to the bag.
4) Mush the strawberry in the bag again for 1 minute. TRY NOT TO MAKE IT FOAM!!!!
5) Assemble your filtration apparatus as shown.
6) Pour the strawberry slurry into the filtration apparatus and let it
drip directly into your test tube.
7) SLOWLY pour 15mL of cold rubbing alcohol down the side of the
cup so that it forms a layer on top. OBSERVE  DNA forms btn.
the layer.
8) Dip the popsicle stick into the tube where the strawberry
extract and alcohol layers come into contact with each other
and pull it out. Allow for it to sit for a minute. OBSERVE 
9) Answer the questions on the back of this lab sheet.
DNA Extraction: Strawberry
Name:___________________________
Conclusions and Analysis
1) It is important that you understand the steps in the extraction procedure and why each
step was necessary. Each step in the procedure aided in isolating the DNA from other
cellular materials. Use the background information to help you match each procedure
with its function.
Procedure
Function
A. Filter strawberry slurry through a filter.
_____ to separate DNA from solution
B. Much strawberry with salty/soapy solution.
_____ Separate components of the cell
C. Initial smashing of the strawberry.
_____ Break open cells
D. Addition of cold alcohol to the filtered
extract.
_____ Break up proteins and dissolve cell
membranes
2) What did the DNA look like?
3) Why would it be important for scientists to be able to remove DNA from an organism?
List two reasons.
4) Is there DNA in your food? ________ How do you know?