ElectroMAX™ DH5α-E Competent Cells (Invitrogen™)

ElectroMAX DH5α-E Competent Cells are derived from the DH5α strain and are suitable for transformation by electroporation. It is challenging to achieve high transformation efficiency by electroporation using the standard DH5α strain (chemical transformation is more efficient) thus additional mutations were introduced to create the DH5α-E strain that is able to reach >1 x 10¹⁰ efficiency by electroporation with non-saturating amounts of DNA. Using this strain, 10 to 50 times greater colony number may be obtained in a single transformation than using the chemically competent DH5α cells. Therefore DH5α-E competent cells are ideal for challenging applications, such as generation of cDNA libraries or in transformations with limited DNA input.

ElectroMAX DH5α-E Competent Cells share several key genetic properties. They carry the hsdR mutation to prevent restriction of foreign DNA and the endA1 mutation that increases the yield of plasmid DNA prepared using miniprep protocols. The lacZΔM15 marker provides α-complementation of the ß-galactosidase gene, allowing blue-white screening on agar plates containing X-gal or Bluo-gal. DH5α-E allows efficient transformation of large plasmids and can also serve as a host for M13mp cloning vectors if a lawn of DH5αF′IQ is provided to allow plaque formation. We do not recommended using this strain for direct cloning of methylated genomic DNA.

ElectroMAX DH5α-E Competent Cell features
• Greatly increased plasmid yield and quality due to endA1 mutation
• High-efficiency transformation with plasmids 30 kb in size
• Blue/white screening of recombinant clones due to lacZΔM15
• Ensured insert stability due to recA1 mutation
• hsdR for efficient transformation of unmethylated DNA from PCR applications

Note: A high-voltage electroporation apparatus is required.

Genotype
F^– φ80lacZΔM15 Δ(lacZYA-argF)U169 recA1 endA1 hsdR17(r_K^–, m_K⁺) gal phoA supE44 λ-thi-1 gyrA96 relA1
Genetic marker descriptions

Find the strain and format that fits your needs
DH strains are available in chemically competent and electrocompetent cell formats.
Explore Multishot format for high throughput applications.
MAX Efficiency DH5αF´IQ Competent Cells are available in chemically competent format.
Explore bacterial growth media formats.