Competent Cell Selection Guide

Product	NEB #	Characteristics
Product	NEB #	Characteristics	Strains for Cloning and Subcloning
dam^-/dcm^- Competent E. coli	C2925I C2925H	Dam/Dcm methyltransferase free plasmid growth
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'I^q 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)	C3019P C3019I C3019H	Large plasmid and BAC cloning DH10B™ derivative
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
Strains for Protein Expression
NEBExpress® Competent E. coli (High Efficiency)	C2523I C2523H	Versatile non-T7 expression strain Protease deficient
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
BL21 Competent E. coli	C2530H	Routine non-T7 expression
T7 Express Competent E. coli (High Efficiency)	C2566I C2566H	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/I^q Competent E. coli (High Efficiency)	C3013I	T7 expression Protease deficient Highest level of expression control
SHuffle® T7 Competent E. coli	C3026J	T7 expression/K12 strain Enhanced capacity to correctly fold proteins with multiple disulfide bonds in the cytoplasm
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
NEBExpress® I^q Competent E. coli (High Efficiency)	C3037I	Control of IPTG induced expression from P_lac, P_tac,P_trcand T5_lac Protease deficient

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.

Applications

Categories

Time for Change

Tools

Resources

Competent Cell Selection Guide