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  • Current: Aug 22, 2022

Competence

In microbiology and molecular biology, competence refers to the ability to take up DNA from the environment into a cell.

Escherichia coli competent cells are commonly used for transformation in molecular biology. Salts (e.g., CaCl2 and MgCl2) are often used to increase the competence of E. coli because salt treatment neutralizes negative charges of cellular membrane and DNA, enhancing their contact.


Public domain image of competent cell preparation

Definitions in the literature

  • The ability to take up DNA from the environment (to be transformed) [1].
  • competent (in microbiology). Describing a bacterial cell that is able to take up a molecule of DNA in the process called transformation (sense 1). Typically, competence is restricted to certain strains of bacterial species, and to certain stages of the growth cycle when the competence-specific proteins are synthesized by the bacterial cells [2].