Thermo Scientific Competent Cells

Confidently competent

Thermo Scientific DH10B, DH5α, and BL21(DE3) competent cells are produced with stringent quality control to enable reliable, consistent performance in cloning workflows. Thermo Scientific DH10B competent cells are also included in the Thermo Scientific CloneJET PCR Cloning Kit and in the Thermo Scientific Phusion Site-Directed Mutagenesis Kit.

Which competent cells are best for my application?

  Thermo Scientific DH10B Competent Cells
Thermo Scientific DH10B Competent Cells
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Thermo Scientific DH5α Competent Cells
Thermo Scientific DH5α Competent Cells
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Thermo Scientific DH5α Competent Cells for Subcloning
Thermo Scientific DH5α Competent Cells for Subcloning
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Thermo Scientific BL21(DE3) Competent Cells
Thermo Scientific BL21(DE3) Competent Cells
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Quantity 20 reactions
10 x 100 µL
20 reactions
10 x 100 µL
40 reactions
4 x 500 µL
20 reactions
10 x 100 µL
Primary applications
  • cDNA library
  • Gene bank construction
  • Cloning large plasmids and BACs
  • Site-directed mutagenesis
  • Subcloning DNA and cDNA
  • Plasmid isolation
  • Subcloning DNA and cDNA
Transformation efficiency
(cfu/µg pUC19 DNA)
> 1x109 > 1x109 > 1x106 > 1x107
Notes Not suitable for preparing unmethylated DNA Not suitable for preparing unmethylated DNA Not suitable for preparing unmethylated DNA Not suitable for maintenance of expression plasmids
Genotype F– mcrA Δ(mrr-hsdRMS-mcrBC) φ80lacZΔM15 ΔlacX74 recA1 endA1 araD139 Δ (ara-leu)7697 galU galK λ– rpsL(StrR) nupG F– φ80lacZDM15 D(lacZYA-argF) U169 recA1 endA1 hsdR17 (rk–, mk+) phoA supE44 l– thi–1 gyrA96 relA1 F– φ80lacZDM15 D(lacZYA-argF) U169 recA1 endA1 hsdR17 (rk–, mk+) phoA supE44 l– thi–1 gyrA96 relA1 F– ompT hsdSB (rB-mB-) gal dcm (DE3)

If you are looking for competent cells for specialized applications, view our Invitrogen competent cells here.

Thermo Scientific competent cell combination kits

Thermo Scientific CloneJET PCR Cloning Kit with DH10B
Phusion Site-Directed Mutagenesis Kit with DH10B

Achieve high transformation efficiencies with Thermo Scientific competent cells

Thermo Scientific DH10B competent cells

Thermo Scientific DH10B competent cells

The transformation efficiencies of DH10B competent cells (Thermo Fisher Scientific), 10-beta competent E. coli I (NEB), and E. cloni 10G cells (Lucigen Corp) were compared using pUC19 DNA and following the manufacturers’ recommended protocols. The transformation efficiency specification for DH10B competent cells is 1.0 x 109 CFU/µg DNA (represented by the red dashed line). The values shown are the averages of five transformations. Error bars represent standard deviations.

Thermo Scientific DH5α competent cells

Thermo Scientific DH5α competent cells

The transformation efficiencies of DH5α competent cells and 5-alpha competent E. coli (NEB) were compared using pUC19 DNA and following the manufacturers’ recommended protocols. The transformation efficiency specification for DH5α competent cells is 1.0 x 109 CFU/µg DNA (represented by the red dashed line). The values shown are the averages of five transformations.

Thermo Scientific DH10B competent cell transformation efficiency in the CloneJET PCR cloning workflow

Thermo Scientific DH10B competent cell transformation efficiency in the CloneJET PCR cloning workflow

A 976 bp PCR product was generated using either Thermo Scientific DreamTaq Green PCR Master Mix (2X) (represented by grey bar) or Thermo Scientific Phusion Hot Start II DNA Polymerase (represented by blue bar) and ligated into a cloning vector according to the manufacturers’ protocols. The transformation efficiency obtained with the control fragment provided with the CloneJET PCR Cloning Kit is represented by the yellow bar. Ligation mixtures were used to transform Thermo Scientific DH10B cells. The expected transformation efficiency of competent cells is >1 x 107 CFU/µg DNA. The transformation efficiency specification of DH10B competent cells with pUC19 DNA is 1 x 109 CFU/µg DNA. The values shown are the average of five transformations. Error bars represent standard deviations.

Efficient recovery of mutants using Thermo Scientific DH10B competent cells

Efficient recovery of mutants

The Thermo Scientific Phusion Site-Directed Mutagenesis Kit has been tested using the control plasmid and control primer mix provided in the kit, in conjunction with Thermo Scientific DH10B competent cells. The primer mix reverts the mutated internal stop codon to a functional codon; a successful mutagenesis reaction results in blue colonies on ampicillin agar plates containing X-Gal and IPTG. A high rate of mutagenesis and high transformation efficiency means that numerous mutants can be directly subjected to sequencing, eliminating additional analysis steps.

Resources

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