DH5 alpha: Difference between revisions
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Like many cloning strains, DH5 alpha has several features that make it useful for recombinant DNA methods. | 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 [[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. | * The ''hsdR17'' mutation eliminates the restriction endonuclease of the EcoKI restriction-modification system, so DNA lacking the EcoKI methylation will not be degraded. DNA prepared from hsdR strains that are wt for [[hsdM]] wil be methylated and can be used to transform wt ''E. coli'' K-12 strains. | ||
* Δ''(lacZ)''M15 is the [[lacZ alpha complementation|alpha acceptor]] allele needed for blue-white screening with many lacZ based vectors. | * 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>. | * recA eliminates homologous recombination. This makes the strain somewhat sickly, but reduces deletion formation and plasmid multimerization<ref>citation needed</ref>. | ||
Revision as of 01:26, 4 April 2008
Alternate Names
Sources
Chromosomal Genotype
fhuA2 Δ(argF-lacZ)U169 phoA glnV44 Φ80 Δ(lacZ)M15 gyrA96 recA1 relA1 endA1 thi-1 hsdR17
Plasmids
Phage
Phenotypes
Construction
Notes
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. DNA prepared from hsdR strains that are wt for hsdM wil be methylated and can be used to transform wt E. coli K-12 strains.
- 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].
- glnV44 is the systematic name for SupE44, an amber suppressor
References
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