Strawberry change-I predict that by using more strawberries than required will make the clumpy DNA strands heavier and harder to distinguish from the liquid solution, vice versa when putting less than the required amount.

-Strawberries are good for dna extraction because their individual chromosomes have eight copies, making it easy to separate by breaking open, cell walls, and it can be viewed with the naked eye

Independent: amount of strawberries mashed, and mixed with the extraction liquid.

Controlled: Type of Ziplock bag, amount of DNA extraction liquid used, bamboo skewer collection tool, amount of time spent mixing the strawberries with the extraction liquid, paper towel filter, the amount of isopropyl alcohol poured with the final mix.

Dependent : DNA visibility, coloring, smell, etc, each time being tested.

1. Pull off all leaves from your strawberries, the put them in a plastic ziplock bag.
2. Gently crush the strawberries with you hands to release the DNA
3. Mix together 2 teaspoons of detergent, 1 teaspoon of salt and 1/2 cup of water in a cup for the extraction liquid
4. Pour the DNA extraction liquid into the bag with the strawberries to further break open the cells.
5. Reseal the bag and gently smash for another minute. 
6. Place the  filter inside the other cup. Open the bag and pour the strawberry liquid into the filter. Twist the filter just above the liquid and gently squeeze the remaining liquid into the cup. 
7. Pour rubbing alcohol into the strawberry mix cup, do not stir or mix it.
8. Within a few seconds, watch for a white cloudy substance (DNA) to develop in the top layer. 
9. Tilt the cup and pick up the DNA using your bamboo skewer.

Exp 1.  DNA was was a small bundle of white strands against the orangey pink mixture , light and easy to pick up with a toothpick.

Exp 1. The DNA was bigger than before, a bunch of light pink strands balled up against the dark reddish pink solution, stuck to the stick better, easier to see.

Exp 1. The DNA was barely visible, very pale, white thread-like strands, very hard to pick up and distinguish from the surface of the mixture, kept slipping off the toothpick.

I was wrong in my hypothesis, the opposite of what I theorized was correct, that adding more crushed strawberries into the mixture does not make the resulting DNA mix diluted, or strands harder to see, but instead helps bunch together the dna contained in our mix.

Changing the amount of strawberries used for an experiment to test extracting DNA from strawberries affects the final product depending on how many strawberries are provided to be broken down from their cells, and adding more than the normal amount is actually a good idea.

i applied these steps during my experiment

1. Pull off all leaves from your strawberries, the put them in a plastic ziplock bag.
2. Gently crush the strawberries with you hands to release the DNA
3. Mix together 2 teaspoons of detergent, 1 teaspoon of salt and 1/2 cup of water in a cup for the extraction liquid
4. Pour the DNA extraction liquid into the bag with the strawberries to further break open the cells.
5. Reseal the bag and gently smash for another minute. 
6. Place the  filter inside the other cup. Open the bag and pour the strawberry liquid into the filter. Twist the filter just above the liquid and gently squeeze the remaining liquid into the cup. 
7. Pour rubbing alcohol into the strawberry mix cup, do not stir or mix it.
8. Within a few seconds, watch for a white cloudy substance (DNA) to develop in the top layer. 
9. Tilt the cup and pick up the DNA using your bamboo skewer.

For the 1st and 3rd experiments (regular measurements and less than regular measurements) there were no sources of error, but during the 2nd experiment (more than regular measurements) I pressed too hard on the paper filter and it split open, spilling the unfiltered strawberries into the mix. I had to restart the experiment to maintain the integrity of my experiment.

]National Human Genome Research Institute (NHGRI) (.gov)

• UW Genome Sciences
• Science Buddies DIY dna
• Google search and overview

I acknowledge the school for providing me with an opportunity to join science fair, and a space to work on science myself too. that is very nice of them to do.