I think that the DNA from the strawberries that are heated will be affected the most. It might break down or evaporate with the water in the strawberries and be hard to extract.

D.N.A., or deoxyribonucleic acid (pronounced deoxy-rie-bo-nu-clay-ick acid) is like a blueprint for living things, It tells proteins to form into specific shapes to make up different parts of organisms. D.N.A. takes the shape of a double helix (see below) to maximize the efficiency of base pair packing with one full twist every 10 base pairs.

Base pairs are the chemical bonds in the “rungs” of the D.N.A. they are made up of 4 different chemicals: adenine (A), cytosine (C), guanine (G), and thymine (T) which bond together, A with T and C with G.

Base packing is when the D.N.A. starts coiling itself into X shaped chromosomes, by first coiling around histones then proceeding to fold up into coils which fold up again into supercoils and finally coiling tightly into chromosomes.

1. Expose the three samples to the different temperatures 
   1. Sample A: Sous vide (hot water bath) 82℃ for 5 hours
   2. Sample B: Freezer -19℃ for 5 hours
   3. Sample C: Room temperature 22℃ for 5 hours
2. Put all the jars with the strawberry mixture in a water bath at 22℃ for 3 hours

Materials and Procedure

Materials

• 200 grams strawberries without stems
• 400 grams of water 
• 48 grams of dish soap
• 24 grams of kosher salt
• 99% Isopropyl Alcohol
• Hand Blender
• 3 clean Mason jars
• Disposable champagne cups from Dollarama

Procedure for 3 samples

1. Cut all the stems off the strawberries and cut into approx 1 cm cubes totaling 200g
2. Put all the strawberry cubes into a blending cup, add 400g water
3. Use a hand blender to pulverize strawberry cubes into a smoothie consistency, pieces should be the same size or smaller than the seeds.
4. Separate the strawberry into 3 labeled Mason jars, 200 g each 
5. Expose the three samples to the different temperatures 
   1. Sample A: Sous vide (hot water bath) 82℃ for 5 hours
   2. Sample B: Freezer -19℃ for 5 hours
   3. Sample C: Room temperature 22℃ for 5 hours
6. Put all the jars with the strawberry mixture in a water bath at 22℃ for 3 hours
7. Mix 48g of soap, 24g of salt, 80g water in a cup
8. Add the salt and dish soap to the now room temperature mashed up strawberries 
9. Stir in the salt and dish soap being careful not to make too many soap bubbles 
10. Strain the strawberry mixture with a tea strainer into labeled cups
11. Pour rubbing alcohol slowly down the side of the cups using a squeeze bottle
12. Observe what happens when the D.N.A. comes to the surface of the alcohol layer

While comparing the three groups, I noticed that the Room Temperature and the Cold DNA were very similar, they were both intact with a little stray DNA floating around. The DNA from the heated strawberries was very broken up and hard to take out of the alcohol even with multiple different tools such as a kebab skewer and a spoon. The DNA from the strawberries that I froze fell apart a little when we tried to take it out of the alcohol. There were no problems when we took the room temperature DNA out with a spoon but the stray DNA was harder to take out. All the DNA was hard to weigh because some of the liquid came out with the DNA, so that’s why there is no measurement for the amount of DNA that was extracted.

I was looking into D.N.A., more specifically how temperature could affect D.N.A. and its extraction. I’m really interested in microscopic things like germs, cells and D.N.A. because it seems impossible that something could be that small, and I want to know why anything would need to be that small. My question was How can temperature affect D.N.A.? and I thought that the D.N.A. that had been heated would be hardest to extract because it might dissolve in the water inside the organism and evaporate. I researched how to extract D.N.A. on the internet and found out that it’s fairly easy to extract D.N.A. from strawberries with household items.

To extract D.N.A. from strawberries, take off all the leaves from 2 strawberries, then you need to mash them up in a resealable bag, mix 2 tsp of dish soap 1 tsp of salt and ½ cup of water in a drinking cup and mix it all up, pour the extraction liquid into the bag containing the mashed up strawberries and mash some more, place a tea strainer on top of a new plastic cup and stir until most of the liquid has gone through, pour ⅓ cup down the side of the cup do not mix or stir. Within a few seconds you will see a cloudy substance appear on top of the alcohol layer, this is the D.N.A.

The D.N.A of the strawberries that were heated was affected the most (see pictures), supporting my hypothesis; it was all broken up and spread out, the other two groups were similar (see pictures) and not broken up too much. The sources of error were letting the extracting liquid sit for too long because it thickens over time and makes it hard to filter properly and pouring the alcohol too fast or too slow because if you pour too fast then it gets mixed in too much and if you pour too slow it doesn't get mixed in enough to separate the D.N.A. from the water and cell tissue (the other parts of the strawberry). In the future, I might look into how hot the strawberries have to be for how long to actually make a difference, and maybe use liquid nitrogen to flash-freeze the strawberries before extracting the D.N.A..

My thesis was proved and the heated strawberries’ D.N.A. was most affected, it was broken up to the point that you probably couldn't send it to a lab for testing and figure out who murdered Mr. Banana.

Display

Detective Orange is out to find the culprit. Three strawberries are suspected, and they’re all working together making them one of the most dangerous gangs in the world. These 3 berries all know how to conceal their DNA but only the true culprit really concealed their DNA properly, the rest are decoys. Three cells were found, one in the desert, one in the arctic, and one in an old house, and it’s up to Detective Orange to figure out who did it. (DUN DUN DUN)

Researched Application

In the real word, the police can use your DNA to track you down. Scientists also extracted the world’s oldest DNA from a frozen mammoth, it was 1.65 million years old and they broke a world record! The record was broken on Feb 17 2021.

• The alcohol might not have been able to be poured at the same speed for each sample. If we were to repeat the experiment, we might time it. 
• The jars for putting the strawberry puree into were slightly different weights, although we did use the same brand and size. 

1. The Molecule of Life! Howie Baum. University of Cincinnati. Viewed February 2024.
2. A mammoth discovery: oldest DNA on record from million-year-old teeth. Benjamin Thompson &Shamini Bundel. Nature Podcast. February 17, 2021.
3. Base pair packing Scitable by Nature Education
4. How many base-pairs per turn does DNA have in solution and in chromatin? Some theoretical calculations. National Institutes of Health.
5. Oldest non-human DNA | Guinness World Records Feb 17 2021.
6. The DNA Book, Discover What Makes You You. Professor Alison Woollard and Dr. Sophie Gilbert. DK Publishing. 2020.

?