Intact Genomics (ig®) DirectPlate™ Competent cells offer simple, fast, and robust results for your DNA transformation needs. DirectPlate™ BL21(DE3) chemically competent E. coli cells are a perfect choice for researchers looking to simplify their transformation workflow by eliminating heat shock, lengthy incubations, and time-consuming outgrowth procedures. Simply mix and directly plate! DirectPlate™ BL21(DE3) chemically competent E. coli cells provide higher transformation efficiency than any competitor‘s similar product and are suitable for high-efficiency transformation in a wide variety of applications such as cloning, protein expression and sub-cloning.

DirectPlate Protocol Comparison 2022


Competent cell type:             Chemically competent
Species:                                E. coli
Format:                                 Tubes
Transformation efficiency:      ≥1 x 108 – 109 cfu/µg pUC19 DNA
Blue/white screening:            No
Shipping condition:                Dry ice

Reagents Needed for One Reaction

DirectPlate™ BL21(DE3) competent cell:              50 µl
DNA (or pUC19 Control, 10 pg/µl):                          1 µl


DirectPlate™  BL21(DE3) competent cells:          -80 ºC
pUC19 control DNA:                                             -20 ºC


F–ompT hsdS(rB– mB–) gal dcm λ(DE3)

Quality Control

Transformation efficiency is tested by using the pUC19 control DNA supplied with the kit and using the high-efficiency transformation protocol. Transformation efficiency should be greater than 1×108 – 109 CFU/µg pUC19 DNA. Untransformed cells are tested for appropriate antibiotic sensitivity.

General Guidelines

Follow these guidelines when using DirectPlate™ BL21(DE3) chemically competent E. coli.

  • Handle competent cells gently as they are highly sensitive to changes in temperature or mechanical lysis caused by pipetting.
  • Thaw competent cells on ice, and transform cells immediately following thawing. After adding DNA, mix by gently pipetting up and down a few times.

Comparison Testing

Intact Genomics has performed extensive comparison testing to prove our DirectPlate™ BL21(DE3) chemically competent cells have the highest transformation efficiency on the market.1019-12 1019-36