DNA Extraction

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DNA Extraction
To study DNA and learn how our genes function,
scientists must be able to work with DNA itself,
outside the protective walls of the nucleus and
cell membrane. So researchers have learned to
separate (to isolate or extract) - DNA from the
proteins and other substances in the cell.
Kristin Darden, Janelle Moran, Deb Semmler
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Before we get into this, though, lets do a bit
of review.

• What is DNA?
• Deoxyribonucleic Acid
• Thats a mouthful. Rather than going through a
  long drawn out explanation, try this Tour of the
  Basics to refresh your memory.

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• DNA is a hardy molecule, and one of the largest
  known. To work with it, we need to extract it
  from the other cellular materials.

Us old folks will remember Oliver Hardy. Get it-
Hardy? ?
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So what would you use the isolated DNA for?

• Extraction of DNA is often an early step in many
  diagnostic processes used to detect bacteria and
  viruses in the environment as well as diagnosing
  disease and genetic disorders.

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Thats great, but Im not a geneticist. Why would
I do this process in my class?

• Cuz DNA is cool to look at with your students!

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Okay, Im listening- so what is DNA Extraction?

• Simply put, DNA extraction is the removal of
  deoxyribonucleic acid (DNA) from the cells or
  viruses in which it normally resides.

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So how do I extract the DNA?

• Start by breaking the cells open to expose the
  DNA within.
• Then remove the nuclear membrane lipids by adding
  a detergent.
• Finally precipitate the DNA with an alcohol. This
  step will also remove alcohol-soluble salts.

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Yeah, right- want to run that by me again?

• Its not as difficult as it sounds.
• Any age student can do it- from kindergarten to
  AP Biology students.
• It doesnt require any fancy laboratory
  equipment, if you dont have it.
• You can make it as simple or as complex as youd
  like.

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Watch this to see how simple it can be.
strawberry extraction
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• Now obviously, that was a bit too simple for your
  intermediate classes, so heres another video
  that gives you an idea for that.

Kiwi extraction demo
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WHERE DOES THIS FIT?http//www.doe.in.gov/standar
ds/core.html
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Resources for lessons plans, tutorials, videos,
labs

• Virtual DNA isolation lab this is an excellent
  hands-on presentation that can be used as an
  introduction or review of the DNA isolation lab.
• DNA isolation lab this is the lab we did in the
  preparation of our DNA for gel electrophoresis.
  Copies of the PCR lab and gel electrophoresis are
  also included.
• How to Extract DNA from Anything is a good choice
  if you would want to make comparisons about the
  different amounts of DNA formed from different
  organisms or you would like to vary some of the
  reagents.
• Make Your Own DNA Necklace is a fun activity- you
  can even sell them around Valentines Day as a
  fund raiser- i.e. Why Give Candy and Flowers-
  Give Your Loved One a Piece of Yourself!

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More Resources

• DNA Overview explains what DNA is and includes
  lots of additional information.
• NOVA this Nova site has videos (good for middle
  to high school age) and it includes classroom
  activities, links to books, case studies, etc.
• From the Beginning- from early elementary to
  college, this site explains pretty much anything
  you would want to know about genetics.