The National Institutes of Health (NIH) Guidelines for Research Involving Recombinant or Synthetic Nucleic Acid Molecules (NIH Guidelines) states that with some exceptions, the experimental use of Escherichia coli (E. coli) K-12 Host-Vector Systems and its derivatives are exempt from the IBC review and approval requirements of the NIH Guidelines.

These exemptions apply provided that: (i) the Escherichia coli host does not contain conjugation proficient plasmids or generalized transducing phages; or (ii) lambda or lambdoid or Ff bacteriophages or nonconjugative plasmids are used as vectors. However, experiments involving the insertion into Escherichia coli K-12 of DNA from prokaryotes that exchange genetic information with Escherichia coli may be performed with any Escherichia coliK-12 vector (e.g., conjugative plasmid). When a non-conjugative vector is used, the Escherichia coli K-12 host may contain conjugation-proficient plasmids either autonomous or integrated, or generalized transducing phages. For these exempt laboratory experiments, Biosafety Level-1 physical containment conditions are recommended.

However, the following categories are not exempt from the NIH Guidelines: (i) experiments described in Section III-B which require NIH OSP and Institutional Biosafety Committee approval before initiation, (ii) experiments involving the cloning and expression of DNA from Risk Groups 3, 4, or restricted organisms or cells known to be infected with these agents, (iii) large-scale experiments (e.g., more than 10 liters of culture), and (iv) experiments involving the cloning of toxin molecule genes coding for the biosynthesis of molecules toxic for vertebrates.

Included is a list of some commonly used strains of E. coli, and the NIH Guidelines category applicable to those strains.

The following E. coli laboratory strains are K12 or derived from K-12 and therefore most research utilizing these strains is exempt from the NIH Guidelines. (RG1, Exempt, NIH Guideline III-F, F-8, Appendix C-II)