Need help? Find application-specific tips, troubleshooting help, and technical resources within our new Cloning Support Center.

MAX Efficiency™ DH5α Competent Cells

Catalog number:  18258012

 Related applications:


Error loading your content!

  Catalog number
Select a plan
Unit size
Price ({{currency}}) Availability Qty
{{product.sku}} {{product.sku}} also known as {{product.formattedSku}} 
Pro add-ons

Your on-site stock

›› {{supplyCenter.scName}}({{scProduct.stockOnHand}} In stock)
›› {{supplyCenter.scName}}(Out of stock)
›› {{supplyCenter.scName}}
This item is not currently available on-site. Depending on your Supply Center settings you may be able to add the item to cart above else use the Order Non-Stocked Items' tab on the Supply Center home page.
Back to top


MAX Efficiency DH5α Competent Cells are a well-known, versatile strain that can be used in many everyday cloning applications. In addition to supporting blue/white screening, recA1 and endA1 mutations in DH5α cells increase insert stability and improve the quality of plasmid DNA prepared from minipreps.

Features of MAX Efficiency DH5α Competent Cells include:

• Transformation efficiency up to 1 × 109 transformants/µg plasmid DNA
• High plasmid yield from the DH5α (endA1) E. coli strain
• Blue/white screening capable (lacZΔM15)
• Greater insert stability (recA1)

About MAX Efficiency DH5α Competent Cells
MAX Efficiency DH5α Competent Cells have been prepared by a proprietary modification of the procedure of Hanahan (1983). These cells are suitable for the construction of gene banks or for the generation of cDNA libraries using plasmid-derived vectors. The Φ80lacZΔM15 marker provides α-complementation of the β-galactosidase gene from pUC or similar vectors, and can therefore be used for blue/white screening of colonies on bacterial plates containing Bluo-gal or X-gal. DH5α cells are capable of being transformed efficiently with large plasmids, and can also serve as a host for the M13mp cloning vectors if a lawn of DH5α-FT, DH5αF′, DH5αF′IQ, JM101, or JM107 is provided to allow plaque formation.

Genotype: F- Φ80lacZΔM15 Δ(lacZYA-argF) U169 recA1 endA1 hsdR17 (rk-, mk+) phoA supE44 λ-thi-1 gyrA96 relA1

Find the strain and format that you need
DH5α cells are available with a variety of transformation efficiencies and in both electrocompetent and chemically competent formats and in single-use aliquots.

Subcloning Efficiency DH5α Competent Cells—our most economical competent cell for everyday use
Library Efficiency DH5α Competent Cells—economical and for use with difficult-to-transform DNA
MAX Efficiency DH5α-T1R Competent Cells—T1 phage resistant, >109 transformants/µg plasmid DNA
One Shot MAX Efficiency DH5α-T1R Competent Cells—single-use format, T1 phage resistant, >109 transformants/µg plasmid DNA
ElectroMAX DH5α Competent Cells—electrocompetent with >1010 transformants/µg plasmid DNA and ideal for cDNA libraries or larger inserts
For Research Use Only. Not for use in diagnostic procedures.


Competent Cell Type: Chemically Competent
Species: E. coli
Format: Tube(s)
Transformation Efficiency: > 1x10^9
Bacterial or Yeast Strain: DH5α
Product Line: DH5a, MAX Efficiency™
Blue-White Screening: Yes
Cloning Methylated DNA: No
Cloning Unstable DNA: Not Suitable for cloning unstable DNA
F' Episome (to make ssDNA): Lacks F' Episome
High Throughput Compatibility: Not High Throughput-Compatible (Manual)
Improves Plasmid Quality: Yes
Preparing Unmethylated DNA: Not Suitable for preparing unmethylated DNA
Product Size: 200 µL
Propagating ccdB Vectors: Not for ccdB vector propagation
Reduces Recombination: Yes
T1 Phage - Resistant (tonA): No
Shipping Condition: Dry Ice

Contents & storage

• Max Efficiency DH5α Competent Cells: 5 vials, 200 µl each (total of 1 ml)
• pUC19 DNA (0.01 µg/ml): 1 vial, 100 µl
• S.O.C. medium: 2 bottles, 6 ml each

Store Competent Cells at -80°C. Store pUC19 DNA at -20°C. Store SOC Medium at 4°C or at room temperature.


Manuals & protocols