New England Biolabs: Reagents for the Life Sciences Industry

Competent Cell Selection Guide

ProductNEB #Characteristics
Strains for Cloning and Subcloning
NEB® Stable Competent E. coli (High Efficiency)C3040H
C3040I
  • High quality plasmid preparations due to endA mutation
  • Rapid growth recA strain
  • T1 phage resistance (fhuA)
  • Value pricing
  • Free of animal products
NEB® Turbo Competent E. coli (High Efficiency)C2984H
C2984I
  • Fastest growth – colonies visible after 6.5 hours
  • Plasmid preparation after 4 hours
  • Tight control/expression of toxic genes (F´lacI8)
NEB® 5-alpha Competent E. coli (High Efficiency)C2987H
C2987I
C2987P
C2987R
C2987U
  • Versatile cloning strain
  • DH5α™ derivative
NEB® 5-alpha F' Iq Competent E. coli (High Efficiency)C2992H
C2992I
  • Toxic gene cloning
  • F´ strain with extremely high transformation efficiency
NEB® 10-beta Competent E. coli (High Efficiency)C3019H
C3019I
  • Large plasmid and BAC cloning
  • DH10B™ derivative
dam-/dcm- Competent E. coliC2925H
C2925I
  • Dam/Dcm methyltransferase free plasmid growth
Strains for Protein Expression
NEB® Express Competent E. coli (High Efficiency)C2523H
C2523I
  • Versatile non-T7 expression strain
  • Protease deficient
NEB® Express Iq Competent E. coli (High Efficiency)C3037I
  • Control of IPTG induced expression from Plac, Ptac,Ptrc and T5lac
  • Protease deficient
T7 Express Competent E. coli (High Efficiency)C2566H
C2566I
  • Most popular T7 expression strain
  • Protease deficient
T7 Express lysY Competent E. coli (High Efficiency)C3010I
  • T7 expression
  • Protease deficient
  • Better reduction of basal expression
T7 Express lysY/Iq Competent E. coli (High Efficiency)C3013I
  • T7 expression
  • Protease deficient
  • Highest level of expression control
T7 Express Crystal Competent E. coli (High Efficiency)C3022I
  • T7 expression
  • Protease deficient
  • SeMet labeling for protein crystallography
SHuffle® Express Competent E. coliC3028J
  • Protease deficient/B strain
  • Enhanced capacity to correctly fold proteins with multiple disulfide bonds in the cytoplasm
SHuffle® T7 Express Competent E. coliC3029J
  • T7 expression
  • Protease deficient/B strain
  • Enhanced capacity to correctly fold proteins with multiple disulfide bonds in the cytoplasm
SHuffle® T7 Express lysY Competent E. coliC3030J
  • T7 expression
  • Protease deficient/B strain
  • Tightly controlled expression of toxic proteins
  • Enhanced capacity to correctly fold proteins with multiple disulfide bonds in the cytoplasm
SHuffle® T7 Competent E. coliC3026J
  • T7 expression/K12 strain
  • Enhanced capacity to correctly fold proteins with multiple disulfide bonds in the cytoplasm
BL21 Competent E. coliC2530H
  • Routine non-T7 expression
BL21(DE3) Competent E. coliC2527H
C2527I
  • Routine T7 expression
Lemo21(DE3) Competent E. coliC2528J
  • Tunable T7 expression for difficult targets
NiCo21(DE3) Competent E. coliC2529H
  • Improved purity of target proteins isolated by IMAC

There are many properties to consider when choosing a strain for your experiments. Requirements such as plasmid preparation, blue-white screening, cytoplasmic disulfide bond formation and fast colony growth necessitate specific strain choices. Please check the Strain Properties Chart for a particular experiment.

DH5α™ and DH10β™ are trademarks of Invitrogen.
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