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Thursday, November 11, 2004

More on DNA Technology and Biotechnology

Mutants are descendants of a cell that does not successfully repair a mutation.
Wild Types are cells normally found in nature
Methods to recognize mutants:
1) Positive or Direct selection- when something is introduced into a bacterial population that should kill them, unless they have a mutation that makes them resistant.
2) Negative or Indirect selection- when a mutation results from requirements that the rest of the population does not need. (This usually has a growth factor requirement)
3) Ames Test- A test of mutagenic effects of a chemical of interest. Salmonella is mutated to metabolize differently than wild type. If the test chemical is a mutagen, these mutated salmonella will "mutate" back to metabolize like the wild type.
However, sensitivity may cause false-positives in the Ames Test.
History and Procedure of the Ames Test
Biotechnology- involves the intentional modification of genomes of an organism, by natural and biological modification. There are three basic goals:
1) To eliminate the undesirable phenotype
2) To combine beneficial traits of two or more organisms to create valuable new organisms
3) To create organisms to synthisize products of human need.
Note: Take time to read Barbara Kingsolver's "A Fist in the Eye of God". It's an essay from her new book "Small Wonders", that talks of biotechnology in several viewpoints. Barbara Kinsolver has a phD in Microbiology and Ecology.
You can read more about Barbara Kinsolver here

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