FRUIT LOOPS

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FRUIT LOOPS

• STRAWBERRY DNA EXTRACTION

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Did You Know

• There are about 2 meters of DNA in each of your
  cells.
• If all the DNA in your body was put end to end,
  it would reach to the sun and back over 600 times
  (0.983?289?8912 AU - 1.016?710?3335 AUgt avg
  150M km / 93M miles x 600 90B km / 720M miles
  gt 45 trillion cells this is disputed, but
  definitely in the 10s of trillions 1013.
• Human DNA is 98 identical to chimpanzee DNA
• My DNA is 99 identical to your DNA
• Institute for Stem Cell Research

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Why Use A Strawberry???

• Each strawberry cell has a lot of DNA!
• Domestic (store-bought) strawberry cells are
  octoploids (8 copies of each chromosome)
• 7 chromosomes per gamete gt 56 chromosomes
• More or Less variability than diploid?
• Our cells only have 2 copies of each chromosome.

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Lab materials.

• Freezer bags
• 1 strawberry
• DNA extraction buffer
• Filter paper
• Funnel
• Ice cold 99 isopropyl alcohol
• Test tube
• Paper clip (or a similar object)

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Why do we crush the strawberries?

• To break cell walls.

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How do we make extraction buffer?

• - Combine 100 mL shampoo (w/o conditioner)
• 15 g non-iodized kitchen salt
• Fill with water to 1 Liter
• THIS WILL MAKE 1 LITER OF EXTRACTION BUFFER

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Et voila, cest ca Un buffer
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Why do we add soap to the extraction buffer?

• To break down/emulsify the lipids that make up
  the cell membrane and nuclear membrane.
• Once we break down the nuclear membrane, we have
  access to the DNA.

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What is the purpose of adding salt to our
extraction buffer?

• Salt will disassociate into and ions.
• This will uncoil the negatively charged DNA
  molecule.

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Why do we use alcohol during the final steps of
the lab?

• Alcohol is a polar substance.
• DNA is nonpolar, therefore, it is insoluable in
  alcohol.
• As a result, the DNA will precipitate (separate)
  forming long rope-like DNA molecules in the
  alcohol.

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PROCEDURE

• Smash fruit in freezer bag.
• Add 10 mL of extraction buffer. Continue
  mashing.
• Filter (with filter paper) smashed fruit into a
  test tube.
• Add 10 mL of alcohol to test tube.
• DNA will precipitate. Use paper clip to grab
  DNA!!!