Strain |
Source |
Resistance |
Comments |
58F3 |
Genentech |
None |
Used with tphac promoter vectors for expression of membrane proteins. W3110 background. Genotype: Δfhu Δlon galE rpoHt ΔclpP lacIq ΔompTDΔslyD. See: Kim et al. PLoS ONE (2012) 7(4) e35844. |
ArcticExpress(DE3) |
Agilent Technologies (formerly Stratagene) |
None* |
Contains genes for cold-adapted chaperonins (cpn60, cpn10) to enhance folding/growth at low temperatures and increase soluble protein yields. See Instruction manual for expression protocol. Co-purification of cpn60/10 with the protein of interest is a common problem. Incubation with MgCl2/ATP/KCl facilitates separation. See: R. E. Joseph; A. H. Andreotti, Protein Expr. Purif. 2008, 60, 194–197. |
ArcticExpress(DE3)RIL |
Agilent Technologies (formerly Stratagene) |
None** |
Contains genes for cold-adapted chaperones and tRNAs for rare Arg/Ile/Leu codons. See Instruction manual for expression protocol. See above note on purification strategy. |
BL21(DE3) |
Agilent Technologies (formerly Stratagene) |
None |
General purpose T7 expression strain. |
BL21(DE3)pLysS |
Agilent Technologies (formerly Stratagene) |
Cap |
Contains gene for T7 lysozyme. T7 lysozyme inhibits T7 RNA polymerase and allows tighter expression control. |
BL21(DE3)Star |
Life Technologies (formerly Invitrogen) |
None |
Contains mutation in RNaseE to improve stability of mRNA transcripts and increase yield. |
BL21CodonPlus(DE3)RIL |
Agilent Technologies (formerly Stratagene) |
Cap |
Contains tRNAs for rare Arg (AGA, AGG), Ile (AUA), and Leu (CUA) codons that often restrict translation from AT-rich genomes. |
BL21CodonPlus(DE3)RP |
Agilent Technologies (formerly Stratagene) |
Cap |
Contains tRNAs for rare Arg (AGA, AGG) and Pro (CCC) codons that often restrict translation from GC-rich genomes. |
C41(DE3) |
Sanders lab |
None |
Mutant BL21 strain shown to be effective for expression of toxic and membrane proteins. |
C41(DE3)pLysS |
Made in-house from C41(DE3) |
Cap |
Mutant BL21 strain shown to be effective for expression of toxic and membrane proteins. Contains pLysS for tighter expression control. |
C43(DE3) |
Sanders lab |
None |
Mutant BL21 strain shown to be effective for expression of toxic and membrane proteins. |
Origami B(DE3) |
EMD Millipore (formerly Novagen) |
Kan/Tet |
BL21 derivative with mutant thioredoxin reductase (trxB) and glutathione reductase (gor) genes to enhance cytosolic disulfide bond formation. Use of a thioredoxin fusion tag further enhances the formation of disulfide bonds in the cytoplasm. |
Origami B(DE3) |
EMD Millipore (formerly Novagen) |
Kan/Tet |
BL21 derivative with mutant thioredoxin reductase (trxB) and glutathione reductase (gor) genes to enhance cytosolic disulfide bond formation. Use of a thioredoxin fusion tag further enhances the formation of disulfide bonds in the cytoplasm. |
Rosetta2(DE3) |
EMD Millipore (formerly Novagen) |
Cap |
Enhances the expression of eukaryotic proteins that contain codons rarely used in E. coli. Contains tRNAs for 7 rare codons (AUA, AGG, AGA, CUA, CCC, GGA, CGG). |
Rosetta2(DE3)pLysS |
EMD Millipore (formerly Novagen) |
Cap |
Enhances the expression of eukaryotic proteins that contain codons rarely used in E. coli. Contains tRNAs for 7 rare codons and pLysS for tighter expression control. |
SoluBL21(DE3) |
Genlantis |
None |
Improves expression of toxic clones and proteins in soluble form. |
Tuner(DE3) |
EMD Millipore (formerly Novagen) |
None |
BL21 lacZY deletion that enables tuning expression levels by adjusting IPTG concentration. |