Strawberry DNA Extraction

Good evening scientists! We just did my all time favorite experiment from my Middle School Science Days, Strawberry DNA Extraction! My little scientist has been very interested in learning about DNA the past few days so it was the perfect time to introduce him to DNA extraction. Please try this with you kiddos they are sure to love it.

MaterialsStrawberry DNA Extraction (8)

Safety Goggles

Strawberries

Gallon Ziploc Bag

Table Salt

Soap (We used dish soap, shampoo and hand soap work too)

Coffee Filter

Small Clear Container (We used a Condiment Cup)

Rubbing Alcohol (Store in the freezer to get it really cold. We used 90%, I have used the 70% kind in the past it works as well just might take it a tad longer)

Toothpick

Optional: Medicine or  Eye Dropper to add the rubbing alcohol at the end. (Throw away when done)

Investigation

**Your child needs to be fully supervised at all times and wear safety goggles for this investigation due to the chemical rubbing alcohol.**

  1. Pick a large strawberry or several smaller ones, place them in a gallon size Ziploc bag and smash them up.Strawberry DNA Extraction (13)
  2. Add a few squeezes of soap (We used dish soap roughly 1/4 cup) and table salt (about a 1 Tablespoon) to the bag and mix up the contents until they are slightly soapy.

3. Place a coffee filter into a small clear container. Pour some of the liquid from your Ziploc into the filter (try not to get the big pieces, but if they fall in it is ok). Strawberry DNA Extraction (23) 4. Gently squeeze your coffee filter to help the liquid come out.Strawberry DNA Extraction (27) 5. Adults: Pour really cold rubbing alcohol over the filtered strawberry juice until it is covered completely with a small layer. (If it spills, ours did almost each time we did this just clean it well and wash your hands)Strawberry DNA Extraction (29) 6. Watch the juice form small white strips or goo, this is the strawberries’ DNA. Use the toothpick to gently swirl the DNA.

Talking Points

All living things have DNA. DNA (Deoxyribonucleic acid) carries all the genetic information for an organism. A copy of DNA is in each of an organisms cells. People have two copies of each gene that makes up our DNA, strawberries are special because they have eight copies. This makes getting DNA from a strawberry much easier then from a person because there are more copies of the DNA.

Smashing the strawberry up made it easier for the salt and soap to break down the cell walls of the strawberries so that the individual parts were easier to get to. The rubbing alcohol made the DNA strands float out of the strawberry juice as white strands.

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