- Did transformation take place? Explain.
Plates bearing (*) demonstrated growth on plain("P*")
nutrient agar plates, and no growth on tetracycline
("T*") plates. Following treatment to induce
competency, the plasmid pBR322 was inserted into
competent E. coli cells. Resultant platings
demonstrated that the competent wild-type E. coli cells
incorporated the plasmid because growth was
observed on plain ("P**") nutrient agar and
tetracycline (T**") plates. Since growth of E. coli cells
was observed on tetracycline agar following the
addition of the pBR322 plasmid, we can assume that
these E. coli cells were transformed.
- What other steps can be taken to verify that
transformation has ocurred?
The drug-resistant growth of E. coli on tetracycline-
containing media provides confirmation, at the level of
the oragnism's phenotype that the bacteria have been
transformed by the plasmid pBR322. That level of
confirmation is probably sufficient. However, it is
possible to verify that transformation has occurred at a molecular level. The
verification process requires
isolation of the plasmid DNA from the transformed
bacterial cells and the characterization (comparison) of that isolated DNA to a known sample of pBR322 DNA.
|
|
|
AE Partners Collection Index
