DNA Technology

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DNA Technology
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DNA Extraction

• Chemical treatments cause cells and nuclei to
  burst
• The DNA is inherently sticky, and can be pulled
  out of the mixture
• This is called spooling DNA

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Spooled DNA
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Cutting DNA

• Restriction enzymes cut DNA at specific sequences
• Useful to divide DNA into manageable fragments

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Electrophoresis

• DNA can be separated based on size and charge
• The phosphate groups are negatively charged
• DNA is placed in a gel and electricity is run
  through

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Electrophoresis

• Negative DNA moves toward the positive end
• Smaller fragments move farther and faster

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Electrophoresis
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Steps in DNA Sequencing

• Many copies of a single strand of DNA are placed
  in a test tube
• DNA polymerase is added
• A mixture of nucleotides is added some of which
  have dye molecules attached
• Each base (A,T,C,G) has a different color dye

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Steps in DNA Sequencing

• By chance, some dyed nucleotides some regular
  ones are added
• Dye molecules are large and stop the chain from
  growing

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DNA Sequencing

• The result is DNA fragments of multiple sizes
  with colors that can be identified

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DNA Sequencing

• After the gel separates the resulting fragments
  by size, we 'read' the sequence from bottom to
  top.

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Copying DNA

• Polymerase Chain Reaction
• Also called PCR
• A method of making many copies of a piece of DNA

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Steps in Copying DNA

• A DNA molecule is placed in a small test tube
• DNA polymerase that can work at high temps is
  added

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Steps in Copying DNA

• The DNA is heated to separate the two strands
• Primers, short pieces of DNA complementary to the
  ends of the molecule to be copied, are added

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Copying DNA

• The tube is cooled, and DNA polymerase adds new
  bases to the separated strands

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PCR
Large amounts of DNA can be made from a small
starting sample
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Cloning

• Clone- a member of a group of genetically
  identical cells
• May be produced by asexual reproduction (mitosis)

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Cloning organisms

• A body cell from one organism and an egg cell
  from another are fused
• The resulting cell divides like a normal embryo

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Cloning Dolly
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Human Genome Project
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Human Genome Project

• Started in 1990
• Research effort to sequence all of our DNA (46
  chromosomes)
• Over 3.3 billion nucleotides
• Mapping every gene location (loci)
• Conducted by scientists around the world

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HGP Insights

• Only 2 of human genome codes for proteins
  (exons)
• Other 98 (introns) are non-coding
• Only about 20,000 to 25,000 genes (expected
  100,000)
• Proteome organisms complete set of proteins
• About 8 million single nucleotide polymorphisms
  (SNP) places where humans differ by a single
  nucleotide
• About ½ of genome comes from transposons (pieces
  of DNA that move to different locations on
  chromosomes)

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Benefits of Human Genome Project

• Improvements in medical prevention of disease,
  gene therapies, diagnosis techniques
• Production of useful protein products for use in
  medicine, agriculture, bioremediation and
  pharmaceutical industries.
• Improved bioinformatics using computers to help
  in DNA sequencing

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Benefits of Genetic Engineering
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Biotechnology -

• The use of gene science to create new products
  from plants and animals

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BiotechnologyProvides

• Improved food products
• Medical advances
• An enhanced environment

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Herbicide Resistant Crops
CP4 EPSPS Roundup gene Ready

• Soybeans Roundup Ready
• Corn Roundup Ready, Liberty Link
• Cotton BXN, Roundup Ready
• Canola Liberty Link, Roundup Ready

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Biotechnology Breakthroughs

• Insulin (1982)
• First commercial biotech product
• Reliable, inexpensive source of insulin
• Rice
• Enriched with beta-carotene and iron
• Bananas
• Containing edible hepatitis vaccine

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Biotechnology Breakthroughs

• Potatoes with higher solid content
• Garlic that lowers cholesterol
• Fruits and vegetables that reduce risks of cancer
  and heart disease

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Environmental Benefits

• Reduced pesticide use
• Lower energy requirements
• Cleaner water
• Less soil erosion

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