DH5 alpha: Difference between revisions

Revision as of 16:06, 3 April 2008

fhuA2 Δ(argF-lacZ)U169 phoA glnV44 Φ80 Δ(lacZ)M15 gyrA96 recA1 relA1 endA1 thi-1 hsdR17

Transforms with high efficiency. Like many cloning strains, DH5 alpha has several features that make it useful for recombinant DNA methods.

The endA1 mutation inactivates an intracellular endonuclease that degrades plasmid DNA in many miniprep methods^[1].
The hsdR17 mutation eliminates the restriction endonuclease of the EcoKI restriction-modification system, so DNA lacking the EcoKI methylation will not be degraded.
Δ(lacZ)M15 is the alpha acceptor allele needed for blue-white screening with many lacZ based vectors.
recA eliminates homologous recombination. This makes the strain somewhat sickly, but reduces deletion formation and plasmid multimerization^[2].

See Help:References for how to manage references in EcoliWiki.

↑ Taylor, RG et al. (1993) E. coli host strains significantly affect the quality of small scale plasmid DNA preparations used for sequencing. Nucleic Acids Res. 21 1677-8 PubMed
↑ citation needed

@@ Line 15: / Line 15: @@
 ==Notes==
-Transforms with high efficiency.  The ''hsdR17'' mutation eliminates the restriction endonuclease of the EcoKI restriction-modification system, so DNA lacking the EcoKI methylation will not be degraded.
+Transforms with high efficiency.
+Like many cloning strains, DH5 alpha has several features that make it useful for recombinant DNA methods.
+* The [[endA:Gene|endA1]] mutation inactivates an intracellular endonuclease that degrades plasmid DNA in many miniprep methods<ref name='PMID:8479929'/>.
+* The ''hsdR17'' mutation eliminates the restriction endonuclease of the EcoKI restriction-modification system, so DNA lacking the EcoKI methylation will not be degraded.
+* Δ''(lacZ)M15 is the [[lacZ alpha complementation|alpha acceptor]] allele needed for blue-white screening with many lacZ based vectors.
+* recA eliminates homologous recombination.  This makes the strain somewhat sickly, but reduces deletion formation and plasmid multimerization<ref>citation needed</ref>.
 ==References==