Construction and characterization of new cloning vehicles. II. A multipurpose cloning system

Gene. 1977;2(2):95-113.


In vitro recombination techniques were used to construct a new cloning vehicle, pBR322. This plasmid, derived from pBR313, is a relaxed replicating plasmid, does not produce and is sensitive to colicin E1, and carries resistance genes to the antibiotics ampicillin (Ap) and tetracycline (Tc). The antibiotic-resistant genes on pBR322 are not transposable. The vector pBR322 was constructed in order to have a plasmid with a single PstI site, located in the ampicillin-resistant gene (Apr), in addition to four unique restriction sites, EcoRI, HindIII, BamHI and SalI. Survival of Escherichia coli strain X1776 containing pBR313 and pBR322 as a function of thymine and diaminopimelic acid (DAP) starvation and sensitivity to bile salts was found to be equivalent to the non-plasmid containing strain. Conjugal transfer of these plasmids in bi- and triparental matings were significantly reduced or undetectable relative to the plasmid ColE1.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Ampicillin / pharmacology
  • Conjugation, Genetic
  • DNA, Bacterial
  • DNA, Recombinant
  • Escherichia coli / genetics
  • Plasmids*
  • Recombination, Genetic*
  • Tetracycline / pharmacology
  • Transformation, Bacterial


  • DNA, Bacterial
  • DNA, Recombinant
  • Ampicillin
  • Tetracycline