Biotechnology

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					        Biotechnology

The basics, and selected applications
     Recombinant DNA technology
• Restriction endonucleases
  cleave DNA
• Type II cut at specific sites
  (palindromes)
• DNA from different species
  are cut the same way- so
  they can be joined together
• DNA ligase seals the ends
• Many technological
  advances have contributed
  to our understanding of
  gene expression
Agarose gel electrophoresis allows
      rapid analysis of DNA
    Foreign DNA can be “cloned” and
          expressed in bacteria
• E. coli is easily modified
  to take up DNA
• Plasmids are designed
  to act as expression
  vectors
• Plasmids are small;
  artificial chromosomes
  can include large pieces
  of DNA
     Genomic and cDNA libraries
• Collected in bacteria
• Genomic libraries
  contain all of the DNA
• cDNA is produced from
  mRNA (coding
  sequences only)
Hybridization: finding sequences of
              interest
                  • Several hybridization
                    techniques have been
                    developed
                     – Southern “blots” identify
                       genomic sequences
                     – Northern blots- RNA: is
                       gene transcribed?
                     – Western blots detect
                       proteins in a mixture
                     – Southwestern blots!
RFLP and DNA fingerprinting
    DNA sequencing was developed in the
                  1970s
• It’s all automated now!
• Rapid
• Sensitive
• Very high volume
• Does not require
  radioactivity
• Data storage is included
Polymerase chain reaction is rapid and
             versatile
                   • Confirmation of gene
                     sequences (basic
                     research)
                   • Forensic
                   • Medical
                   • Can start with a tiny
                     DNA sample
    Applications of recombinant DNA
               technology
• Expression (and mass
  production) of proteins in
  microbial cells
• Vaccine development
  (subunit, DNA)
• Gene therapy
• Agricultural applications
   – Resistance to herbicides,
     insects, frost…
   – GMOs
   – Transgenic animals
 What is the relationship between science
   and technology?                     (adapted from Kreuzer and Massey, 2005)


• Science                               • Technology
   – Search for knowledge about               – Practical application of
     ourselves and the physical                 knowledge; adapting
     world                                      ourselves to physical world
   – Process: scientific method;              – Process: finding solutions to
     looking for patterns in the                problems; try to control
     physical world; evaluated by               physical world; evaluate by
     how well facts support                     how well it works; limited by
     conclusions; limited by ability            costs and available
     to collect evidence                        technology
   – Discoveries give rise to                 – Advances give rise to
     technological advances                     scientific discoveries
                   Summary
• Science drives technology, and technology drives
  science.
• Biotechnology has been around as long as
  humans have practiced agriculture.
• Biotechnology is used to conduct research,
  develop new products, and improve processes.
• DNA-based technologies have been developed in
  microbes- and beyond.
• As a society, we are responsible for using it wisely
  and ethically.

				
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posted:7/29/2012
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