Competent Cell Selection Guide

There are many properties to consider when choosing a competent cell for your experiments. Requirements such as high-quality plasmid preparations, blue/white screening, cytoplasmic disulfide bond formation, regulated protein expression and fast colony growth necessitate specific strain choices. The following selection chart highlights the characteristics of NEB's strains to help select the optimal strain for a particular experiment.
Product NEB # Characteristics
Strains for Cloning and Subcloning
NEB® Stable Competent E. coli (High Efficiency) C3040I
C3040H
  • 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) C2984I
C2984H
  • Fastest growth – colonies visible after 6.5 hours
  • Plasmid preparation after 4 hours
  • Tight control/expression of toxic genes (F´lacIq)
NEB® 5-alpha Competent E. coli (High Efficiency) C2987U
C2987R
C2987P
C2987I
C2987H
  • Versatile cloning strain
  • DH5α™ derivative
NEB® 5-alpha F'Iq Competent E. coli (High Efficiency) C2992I
C2992H
  • Toxic gene cloning
  • F´ strain with extremely high transformation efficiency
NEB® 10-beta Competent E. coli (High Efficiency) C3019I
C3019H
  • Large plasmid and BAC cloning
  • DH10B™ derivative
dam-/dcm- Competent E. coli C2925I
C2925H
  • Dam/Dcm methyltransferase free plasmid growth
Strains for Protein Expression
NEB® Express Competent E. coli (High Efficiency) C2523I
C2523H
  • 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) C2566I
C2566H
C2566AA
C2566A
  • Most popular T7 expression strain
  • Protease deficient
T7 Express lysY Competent E. coli (High Efficiency) C3010I
C3010AA
C3010A
  • T7 expression
  • Protease deficient
  • Better reduction of basal expression
T7 Express lysY/Iq Competent E. coli (High Efficiency) C3013I
C3013AA
C3013A
  • T7 expression
  • Protease deficient
  • Highest level of expression control
SHuffle® Express Competent E. coli C3028J
  • Protease deficient/B strain
  • Enhanced capacity to correctly fold proteins with multiple disulfide bonds in the cytoplasm
SHuffle® T7 Express Competent E. coli C3029J
  • 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. coli C3030J
  • 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. coli C3026J
  • T7 expression/K12 strain
  • Enhanced capacity to correctly fold proteins with multiple disulfide bonds in the cytoplasm
BL21 Competent E. coli C2530H
  • Routine non-T7 expression
BL21(DE3) Competent E. coli C2527I
C2527H
  • Routine T7 expression
Lemo21(DE3) Competent E. coli C2528J
  • Tunable T7 expression for difficult targets
NiCo21(DE3) Competent E. coli C2529H
  • 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.
SHuffle® is a registered trademark of New England Biolabs, Inc.

Loading Spinner