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DNA
Extraction
 from
Is DNA in My Food???

 DNA is present in the cells of all living
  organisms.
 The process of extracting DNA from a
  cell is the first step for many
  laboratory procedures in
  biotechnology.
 The scientist must be able to separate
  DNA from the unwanted substances
  of the cell gently enough so that the
  DNA does not denature (break up).
DNA Facts
 Each cell contains 9 feet
  of DNA
 In an average meal, you
  EAT approximately
  55,000,000 cells
 This is equal to
  approximately 93,205
  miles of DNA
DNA

 DNA is found in the nucleus of all
  eukaryotic cells
 Most cells have the diploid 2n
  chromosome number
 Many plants are polyploid (contain
  several sets of chromosomes)
 Strawberries are octaploid 8n
DNA

 DNA is enclosed in a nuclear and a
  cell membrane made of
  phospholipids
 DNA is also coiled around proteins
 Both the phospholipid layer and the
  proteins must be removed to see
  DNA
NUCLEUS with DNA
To Extract DNA, You Must
          Remove 

 Cell membrane
 Cytoplasm
 Nuclear membrane
 Proteins
How Do I Begin?

 Place the strawberry in a zip lock bag
  and remove the air
 Squash the berry with your hand to
  begin the process
Cell Membrane

 Cell membranes are
  made of phospholipids
 Phospholipids wont
  dissolve in water
 What do you use in
  your home to remove
  oils from your hands
  or your dishes?
 SOAP or DETERGENT!
Soap & Detergent

 Soap gathers between oil
  and water capturing the oil
  in a bubble called a micelle
 When you wash your hands,
  the soap carries the oils
  away
 Dawn dishwashing works
  BEST to remove
  phospholipid membranes
Soap & Detergent

 By adding a small amount
  of table salt (NaCl) to
  the soap solution, the
  solution can punch holes
  in the nuclear and cell
  membranes
 The soapy solution also
  helps removes proteins
Another Way to Remove
            Proteins
 DNA is tightly coiled around proteins
  called histones
 Proteins must be removed to see DNA
 Enzymes, like the ones found in meat
  tenderizer, can remove protein
Extracting the DNA

 The contents of the
  cell (organelles,
  proteins, etc.) must be
  separated from the
  DNA
 The larger cell parts
  can be removed by
  filtering the solid from
  the liquid
Extracting DNA

 To see DNA, it must be extracted or
  spooled from the remaining liquid you
  filtered
 DNA dissolves in water, but NOT in
  alcohol
 Adding COLD ALCOHOL will cause DNA
  to precipitate (separate out) from the
  liquid filtrate
Collecting the DNA

 The DNA will appear as
  a white precipitate once
  the alcohol is added
 HOLD THE TUBE by the
  TOP, not the bottom so
  the DNA strands wont
  fragment from the
  heat of your hands!
Spooling the DNA

 DNA is sticky and will
  adhere to other
  surfaces
 A glass stirring rod
  can be used to spool
  (remove) the DNA by
  using a turning motion
Strawberry dna extraction

More Related Content

Strawberry dna extraction

  • 2. Is DNA in My Food??? DNA is present in the cells of all living organisms. The process of extracting DNA from a cell is the first step for many laboratory procedures in biotechnology. The scientist must be able to separate DNA from the unwanted substances of the cell gently enough so that the DNA does not denature (break up).
  • 3. DNA Facts Each cell contains 9 feet of DNA In an average meal, you EAT approximately 55,000,000 cells This is equal to approximately 93,205 miles of DNA
  • 4. DNA DNA is found in the nucleus of all eukaryotic cells Most cells have the diploid 2n chromosome number Many plants are polyploid (contain several sets of chromosomes) Strawberries are octaploid 8n
  • 5. DNA DNA is enclosed in a nuclear and a cell membrane made of phospholipids DNA is also coiled around proteins Both the phospholipid layer and the proteins must be removed to see DNA
  • 7. To Extract DNA, You Must Remove Cell membrane Cytoplasm Nuclear membrane Proteins
  • 8. How Do I Begin? Place the strawberry in a zip lock bag and remove the air Squash the berry with your hand to begin the process
  • 9. Cell Membrane Cell membranes are made of phospholipids Phospholipids wont dissolve in water What do you use in your home to remove oils from your hands or your dishes? SOAP or DETERGENT!
  • 10. Soap & Detergent Soap gathers between oil and water capturing the oil in a bubble called a micelle When you wash your hands, the soap carries the oils away Dawn dishwashing works BEST to remove phospholipid membranes
  • 11. Soap & Detergent By adding a small amount of table salt (NaCl) to the soap solution, the solution can punch holes in the nuclear and cell membranes The soapy solution also helps removes proteins
  • 12. Another Way to Remove Proteins DNA is tightly coiled around proteins called histones Proteins must be removed to see DNA Enzymes, like the ones found in meat tenderizer, can remove protein
  • 13. Extracting the DNA The contents of the cell (organelles, proteins, etc.) must be separated from the DNA The larger cell parts can be removed by filtering the solid from the liquid
  • 14. Extracting DNA To see DNA, it must be extracted or spooled from the remaining liquid you filtered DNA dissolves in water, but NOT in alcohol Adding COLD ALCOHOL will cause DNA to precipitate (separate out) from the liquid filtrate
  • 15. Collecting the DNA The DNA will appear as a white precipitate once the alcohol is added HOLD THE TUBE by the TOP, not the bottom so the DNA strands wont fragment from the heat of your hands!
  • 16. Spooling the DNA DNA is sticky and will adhere to other surfaces A glass stirring rod can be used to spool (remove) the DNA by using a turning motion