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Colonial Differentiation between Escherichia coli B and Escherichia coli B/r


A GREAT deal of radiobiological research has been carried out on Escherichia coli, strain B, and its radiation resistant counterpart, Escherichia coli, strain B/r1. Aside from the fact that E. coli B/r demonstrates increased resistance to various physical and chemical agents1–4 when it is compared to the more sensitive parental type, there is little else to distinguish one strain from the other.

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  1. Witkin, E., Genetics, 32, 221 (1947).

    PubMed  PubMed Central  CAS  Google Scholar 

  2. Bryson, V., J. Bact., 56, 423 (1948).

    PubMed  CAS  Google Scholar 

  3. Bryson, V., Bact. Proc., 15 (1949).

  4. Bryson, V., and Davidson, H., Proc. U.S. Nat. Acad. Sci., 37, 784 (1951).

    ADS  Article  CAS  Google Scholar 

  5. Charles, R. L., and Zimmerman, L. N., J. Bact., 71, 611 (1956).

    PubMed  CAS  Google Scholar 

  6. Anderson, E. H., Proc. U.S. Nat. Acad. Sci., 32, 120 (1946).

    ADS  Article  CAS  Google Scholar 

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ZIMMERMAN, L. Colonial Differentiation between Escherichia coli B and Escherichia coli B/r. Nature 180, 1217–1218 (1957).

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