Description
Highlights
- DH5α™ derivative
- Free of animal products
- Efficient transformation of unmethylated DNA derived from PCR, cDNA and many other sources (hsdR)
- Activity of nonspecific endonuclease I (endA1) eliminated for highest quality plasmid preparations
- Resistance to phage T1 (fhuA2)
- Suitable for blue/white screening by α-complementation of the β-galactosidase gene
- Reduced recombination of cloned DNA (recA1)
- K12 Strain
Transformation Efficiency
For C2987H, C2987I, C2987P and C2987U: 1 - 3 x 109 cfu/μg pUC19 DNA
For C2987R: 1 - 5 x 108 cfu/μg pUC19 DNA
Chemically competent E. coli cells suitable for high efficiency transformation in a wide variety of applications. Available in 5 convenient formats:
- Single-use 50 μl vials
- 200 μl vials
- 96-well plate
- 384-well plate
- 12 x 8-tube strips: packed in 12 x 8-Strip Microplate Cluster Tube (Costar™ Cluster Tube System)
For C2987H, C2987I, C2987P and C2987U, SOC Outgrowth Medium is provided.
For C2987R, Outgrowth Medium 1.5 is provided.
Figure 1: DNA effects on transformation efficiency and colony output
The optimal amount of DNA to use in a transformation reaction is lower than commonly recognized. Using clean, supercoiled pUC19, the efficiency of transformation is highest in the 100 pg-1 ng range. However, the total colonies which can be obtained from a single transformation reaction increase up to about 100 ng.
Figure 2: Effect of heat shock time on NEB 5-alpha competent E.coli transformation efficiency
50 μl of competent cells were transformed with 100 pg of pUC19 control DNA following the provided High Efficiency Transformation Protocol except heat shock time varied from 0 to 80 seconds.
Figure 3: Effect of DNA incubation time on NEB 5-alpha competent E.coli transformation efficiency
50 μl of competent cells were transformed with 100 pg of pUC19 control DNA following the provided High Efficiency Transformation Protocol except DNA incubation time varied from 0 to 40 minutes.
Figure 4: Effect of outgrowth medium on transformation efficiency
50 μl of NEB 5-alpha competent E.coli was transformed with 100 pg of pUC19control DNA following the provided High Efficiency Transformation Protocol with the exception of varying the outgrowth medium. NEB SOC outgrowth medium delivers the highest transformation efficiency.
Figure 5: Benefit from the high transformation efficiencies of NEB 5-alpha
The transformation efficiencies of NEB 5-alpha and DH5α were compared using each manufacturers' recommended protocols. Values shown are the average of triplicate experiments.
Genotype
fhuA2::IS2 Δ(mmuP-mhpD)169 ΔphoA8 glnX44 Ï•80d[ΔlacZ58(M15)] rfbD1 gyrA96 luxS11 recA1 endA1 rphWT thiE1 hsdR17
- This product is related to the following categories:
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Cloning Competent Cell Strains
- This product can be used in the following applications:
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USER® Cloning,
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High-throughput cloning and automation solutions,
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Transformation