Editing Bacterial Strains for Protein Expression

== Bacterial Strains for Protein Expression  ==

{| border="1"
|-
| '''Bacterial Strain''' 
| '''Company''' 
| '''Features''' 
| '''Growth Requirements'''
|-
| BL21(DE3)&nbsp; 
| Novagen 
| DE3 lysogen contains T7 polymerase upon IPTG induction. This strain is defficient of lon and omp-t proteases and is therefore suitable for expression of non-toxic genes. 
| There is no tight control over the expression, thus addition of 1% glucose to the growth medium should be considered. (<u>Note</u>: '''1.''' This significantly attenuates growth rates. '''2.''' Higher concentrations of IPTG should be used for induction.)
|-
| BL21(DE3)-pLysS&nbsp; 
| Novagen 
| DE3 lysogen expresses T7 polymerase upon IPTG induction.&nbsp; The pLysS plasmid produces T7 lysozyme to reduce basal level expression of the gene of interest. Thus it is suitable for&nbsp; expression of toxic genes.&nbsp; [''pLysS contains the p15A origin. This origin allows pLysS to be compatible with plasmids containing the ColE1 or pMB1 origin (i.e. pUC- or pBR322- derived plasmids)''.] 
| Chloramphenicol 34ug/ml&nbsp;
|-
| BL21 Star-pLysS&nbsp; 
| Invitrogen 
| This strain is mutated in Rnase E,&nbsp; thus Rnase degradation is reduced, and protein expression may be increased. The pLysS presence allows tight control of expression. Use this strain for both soluble and insoluble protein production. 
| Chloramphenicol 34ug/ml&nbsp;
|-
| BL21-SI&nbsp; 
| Invitrogen 
| T7 polymerase in the DE3 is under control of the salt-inducible proU&nbsp; promoter. Induction of protein production at 0.1-0.5M of NaCl. Helps protein solubility. 
| '''LBON''' medium (LB w/o NaCl), '''30<sup>o</sup>c'''.&nbsp; Expression induction by NaCl, if controlled by a T7 promoter. Otherwise - IPTG.
|-
| BL21-AI&nbsp; 
| Invitrogen 
| BL21-AI was constructed by inserting a chromosomal copy of the T7 RNA polymerase gene under the tight control of the arabinose-inducible araBAD promoter.&nbsp; 
| Tetracyclin 12.5ug/ml&nbsp; Expression induction by arabinose. (If using pET vectors, IPTG is also required!) Glucose will repress this induction.
|-
| Tuner&nbsp; 
| Novagen 
| Contains a mutation in the lac permease (lacZY) gene. This enables adjustable levels of protein expression throughout all cells in a culture. The lac permease (lacY) mutation allows uniform entry of IPTG into all cells in the population, which produces a concentration-dependent, homogeneous level of induction. By adjusting the concentration of IPTG, expression can be regulated from very low levels up to the robust, fully induced levels commonly associated with pET vectors. Lower level expression may enhance the solubility and activity of difficult target proteins. 
| None&nbsp;
|-
| Tuner pLysS&nbsp; 
| Novagen 
| Contains the pLysS plasmid (tighter control over expression) in addition to the lac permease mutation. 
| Chloramphenicol 34ug/ml&nbsp;
|-
| Origami&nbsp; 
| Novagen 
| Origami host strains are K-12 derivatives that have mutations in both the thioredoxin reductase (trxB) and glutathione reductase (gor) genes, which greatly enhances disulfide bond formation in the cytoplasm.&nbsp; 
| Kanamycin 15ug/ml&nbsp; Tetracyclin 12.5ug/ml&nbsp;
|-
| Origami B&nbsp; 
| Novagen 
| Origami B host strains carry the same trxB/gor mutations as the original Origami strains, except that they are derived from a lacZY mutant of BL21. Thus the Origami B strains combine the desirable characteristics of BL21, Tuner&amp;trade; and Origami hosts in one strain background. 
| &nbsp;Kanamycin 15ug/ml&nbsp; Tetracyclin 12.5ug/ml&nbsp;
|-
| Origami B pLysS&nbsp; 
| Novagen 
| &nbsp; 
| 
Kanamycin 15ug/ml&nbsp; 

Tetracyclin 12.5ug/ml 

Chloramphenicol 34ug/ml&nbsp; 

|-
| Rosetta&nbsp; 
| Novagen 
| Rosetta host strains are BL21 lacZY (Tuner&amp;trade;) derivatives designed to enhance the expression of eukaryotic proteins that contain codons rarely used in E. coli. These strains supply tRNAs for the codons AUA, AGG, AGA, CUA, CCC, GGA on a compatible chloramphenicol resistant plasmid. The tRNA genes are driven by their native promoters. 
| Chloramphenicol 34ug/ml&nbsp;
|-
| Rosetta pLysS&nbsp; 
| Novagen 
| &nbsp;In Rosetta(DE3)pLysS the rare tRNA genes are present on the same plasmids that carry the T7 lysozyme. 
| Chloramphenicol 34ug/ml&nbsp;
|-
| Rosetta-gami-pLysS&nbsp; 
| Novagen 
| Rosetta-gami host strains are Origami derivatives that combine the enhanced disulfide bond formation resulting from trxB/gor mutations with enhanced expression of eukaryotic proteins&nbsp; that contain codons rarely used in E. coli. These strains supply tRNAs for AGG, AGA, AUA, CUA, CCC, GGA on a compatible chloramphenicolresistant plasmid. The tRNA genes are driven by their native promoters. In Rosetta gami(DE3)pLysS the rare tRNA genes are present on the same plasmids that carry the T7 lysozyme.&nbsp; 
| 
Kanamycin 15ug/ml 

Tetracyclin 12.5ug/ml&nbsp; 

Chloramphenicol 34ug/ml&nbsp; 

|-
| BL21 CodonPlus&nbsp; 
| Stratagene 
| BL21-CodonPlus-'''RIL''' chemically competent cells carry extra copies of the argU, ileY, and leuW tRNA genes. The tRNAs encoded by these genes recognize the '''AGA/AGG''' ('''arginine'''), '''AUA''' ('''isoleucine'''), and '''CUA''' ('''leucine''') codons, respectively.&nbsp; 
| Tetracyclin 12.5ug/ml Chloramphenicol 34ug/ml
|-
| AD494&nbsp; 
| Novagen 
| AD494 strains are thioredoxin reductase (trxB) mutants of the K12 strain that enable disulfide bond formation in the cytoplasm, providing the potential to produce properly folded active proteins. 
| &nbsp;Kanamycin 15ug/ml&nbsp;
|-
| BL21trxB&nbsp; 
| Novagen 
| &nbsp;BL21trxB strains possess the same thioredoxin reductase mutation (trxB) as the AD494 strains in the protease deficient BL21 background. The trxB mutation enables cytoplasmic disulfide bond formation. 
| &nbsp;Kanamycin 15ug/ml&nbsp;
|-
| HMS174&nbsp; 
| Novagen 
| HMS174 strains provide the recA mutation in a K-12 background. Like BLR, these strains may stabilize certain target genes whose products may cause the loss of the DE3 prophage. 
| None&nbsp;
|-
| NovaBlue(DE3)&nbsp; 
| Novagen 
| NovaBlue(DE3) is a K-12 strain ideally suited as an initial cloning and expression host due to its high transformation efficiency&nbsp; and recA endA mutations, which result in high yields of excellent quality plasmid DNA. It olso contains DE3 for T7 polymerase expression. Ttight regulation of expression is conferred due to the presence of lacI<sup>q </sup>repressor encoded by the F episome. 
| Tetracyclin 12.5ug/ml&nbsp;
|-
| BLR&nbsp; 
| Novagen 
| BLR is a recA<sup>-</sup> derivative of BL21 that improves plasmid monomer yields and may help stabilize target plasmids containing repetitive sequences or whose products may cause the loss of the DE3 prophage. 
| Tetracyclin 12.5ug/ml&nbsp;
|-
| C41(DE3) 
| Lucigen 
| Effective in expressing toxic and membrane proteins from all classes of organisms,including viruses,eubacteria,archaea,yeasts,plants,insects,and mammals. The strain C41(DE3)was derived from BL21(DE3) [E.coli F ompT hsdS B (r B -m B -) gal dcm (DE3)].This strain has at least one uncharacterized mutation that prevents cell death associated with expression of many toxic recombinant proteins. 
| None
|-
| C43(DE3) 
| Lucigen 
| Effective in expressing toxic and membrane proteins from all classes of organisms,including viruses,eubacteria,archaea,yeasts,plants,insects,and mammals. 
| None
|}

<br> 

'''Rosetta 2''' host strains are BL21 derivatives designed to enhance the expression of eukaryotic proteins that contain codons rarely used in ''E. coli''. These strains supply tRNAs for 7 rare codones (AGA, AGG, AUA, CUA, GGA, CCC, and CGG) on a compatible chloramphenicol-resistant plasmid. The tRNA genes are driven by their native promoters. 

'''DE3''' indicates that the host is a lysogen of DE3, and therefore carries a chromosomal copy of the T7 RNA polymerase gene under control of the ''lacUV5'' promoter. Such strains are suitable for production of protein from target genes cloned in pET vectors by induction with IPTG. 

'''pLysS''' strains express T7 lysozyme, which further suppresses basal expression of T7 RNA polymerase prior to induction, thus stabilizing pET recombinants encoding target proteins that affect cell growth and viability. '''Genotype: '''F<sup>-</sup> ''ompT hsdS''<sub>B</sub>(r<sub>B</sub><sup>-</sup> m<sub>B</sub><sup>-</sup>) ''gal dcm'' (DE3) pLysSRARE2 (Cam<sup>R</sup>)<br> 

<br> 

== Strain Features and Vector Compatibility  ==

{| border="0"
|-
| Strain 
| Source 
| Features 
| Growth/expression guidelines 
| Compatible expression vectors
|-
| BL21(DE3) 
| NEB; Novagen; Invitrogen; Stratagene; Genlantis; Lucigen 
| chromosomal DE3 prophage expresses T7 RNA polymerase under control of the lacUV5 promoter; BL21 derivatives lack Lon and OmpT proteases, which may stabilize expression of some recombinant protein 
| exhibits signiﬁcant basal T7 expression, thus addition of 1% glucose to the growth medium is recommended for toxic clones 
| pET or T7 vectors with lacI gene and T7 – lac promoter
|-
| BL21(DE3) pLysS 
| Novagen; Invitrogen; Stratagene; Genlantis; Lucigen 
| same as above, plus the pLysS plasmid produces wild - type T7 lysozyme to reduce basal T7 expression of the gene of interest; pLysS is compatible with plasmids containing the ColE1 or pMB1 origin (most pET vectors) 
| Cam 34 μ g/ml to maintain pLysS 
| pET or T7 vectors with lacI gene and T7 – lac promoter
|-
| Lemo21(DE3) 
| NEB; Xbrane Bioscience 
| pLemo plasmid produces amidase - negative T7 lysozyme ( lysY ) from a tunable promoter ( Prha ); pLemo is compatible with plasmids containing the ColE1 or pMB1 origin (most pET vectors) 
| Cam 34 μg/ml to maintain pLemo; expression trials typically beneﬁt from rhamnose addition 
| pET or T7 vectors with lacI gene and T7 – lac promoter
|-
| T7 Express LysY/Iq 
| NEB 
| T7 RNA polymerase gene encoded within the lac operon; combination of lysY and lacIq control offers strict control of basal T7 expression 
| incompatible with CamR expression vectors 
| pET or other T7 vector, presence of lacI gene is less important
|-
| BL21-AI 
| Invitrogen 
| T7 RNA polymerase gene is controlled by the araBAD promoter; if using a pET vector, IPTG is also required for induction to titrate LacI repressor away from the T7 – lac promoter on the vector <br> 
| T7 gene 1 is induced by L-arabinose; 0.2% glucose will repress 
| recommended for use with Invitrogen pDEST vectors
|-
| BL21 
| Various companies 
| protein expression from non - T7 promoters metabolizes arabinose, but still suitable for membrane expression from ParaBAD 
| none 
| nearly all non - T7 vectors
|-
| NEB Express Iq 
| NEB 
| BL21 derivative, same features as above except additional control of IPTG - inducible promoters suitable for membrane expression from ParaBAD 
| incompatible with CamR expression vectors 
| non - T7 vectors
|-
| TOP10; LMG194 
| Invitrogen 
| K - 12 strains that do not metabolize l-arabinose may provide slight improvement when expressing membrane protein directly from ParaBAD 
| 0.2% glucose will repress expression of toxic proteins 
| pBAD vectors
|-
| EXP strains 
| UCLA, J. Bowie 
| these are TOP10 mutants selected for improved expression of recombinant membrane protein; DE3 prophage has been added to original isolates 
| none 
| nearly all vectors with DE3 strains
|-
| Single Step KRX 
| Promega 
| T7 RNA polymerase gene is controlled by PrhaBAD&nbsp;; induce with 0.1% l-rhamnose; if using pET, pF1A or pF1K vectors, IPTG is also required for induction to titrate LacI repressor away from the T7 – lac promoter on the vector 0.4% glucose in LB plates or starter culture to stabilize toxic clones 
| <br> 
| pET vectors, T7 Flexi vectors (Promega)
|-
| C41(DE3); C43(DE3) 
| Lucigen 
| BL21(DE3) derivatives with much lower levels of T7 RNA polymerase under noninducing and inducing conditions glucose addition is not necessary as with BL21(DE3) 
| <br> 
| pET or other T7 vector, presence of lacI gene is less important
|-
| Tuner; Tuner(DE3) 
| Novagen 
| lacZY derivatives of BL21; the lac permease mutation ( lacY1 ) allows uniform entry of IPTG into all cells in the population, which produces a concentration - dependent level of induction 
| <br> 
| pET or T7 vectors with lacI gene and T7 – lac promoter
|-
| Tuner (DE3) pLysS 
| Novagene 
| expresses T7 lysozyme to control T7 expression in addition to the lac permease mutation 
| <br> 
| pET or T7 vectors with lacI gene and T7–lac promoter
|-
| Rosetta; Rosetta2 
| Novagen 
| Rosetta host strains are BL21 lacZY (Tuner) derivatives designed to enhance the expression of proteins that contain codons rarely used in E. coli&nbsp;; these strains express tRNAs for rare codons on a compatible CamR plasmid 
| Cam 34 μg/ml <br> 
| pET or T7 vectors with lacI gene and T7 – lac promoter
|-
| Rosetta pLysS; Rosetta2 pLysS 
| Novagen 
| in the pLysS strains, the rare tRNA genes and T7 lysozyme gene are carried by the same plasmid 
| Cam 34μg/ml 
| pET or T7 vectors with lacI gene and T7 – lac promoter
|-
| BL21 CodonPlus; (DE3)-RIPL 
| Stratagene 
| RIPL indicates that the cells carry extra copies of the argU , ileW , leuY , and proL tRNA genes for increased recognition of the AGA/AGG (Arg), AUA (Ile), CUA (Leu), and CCC (Pro) codons 
| Cam 50 μg/ml 
| pET or other T7 vectors
|}

<br> 

<br> 

{| border="1"
|-
! Strain 
! Description 
! Application 
! Antibiotic 
resistance 

|-
| AD494 (DE3) 
| thioredoxin reductase (trxB) mutant 
| trxB expression host; 
disulfite bond formation in cytoplasm 

| Kan
|-
| B834 (DE3) 
| methionine auxotroph; 
deficient in lon and ompT proteases 

| general expression host; 
labelling of proteins with 35S-methionine and selenomethionine 

| none
|-
| B834 (DE3) pLysS 
| methionine auxotroph; 
deficient in lon and ompT proteases 

| high-stringency expression host; 
labelling of proteins with 35S-methionine and selenomethionine 

| Cam
|-
| style="vertical-align: top;" | B834 (DE3) pRARE 
| style="vertical-align: top;" | methionine auxotroph; 
deficient in lon and ompT proteases; contains plasmid encoding&nbsp; argU, argW, glyT, ileX, leuW, metT, proL, thrT, thrU &amp;&nbsp;tyrU. 

| style="vertical-align: top;" | high-stringency expression host; 
labelling of proteins with 35S-methionine and selenomethionine; allows expression of genes encoding tRNAs for rare argenine codons AGA and AGG, glycine codon GGA, isoleucine codon AUA, leucine codon CUA,&nbsp;methionine codon AUG,&nbsp;proline codon CCC, threonine codons&nbsp;ACA and ACC, and tyrosine codon UAC 

| style="vertical-align: top;" | Cam
|-
| BB7333 
| deficient in clpX, clpP and lon proteases 
| general prupose expression host with inhibited protein degradation 
| Cam (10µg/ml)
|-
| BL21 
| deficient in lon and ompT proteases 
| general puropose expression host for plasmids which do not use a T7 promoter 
| none
|-
| BL21 AI 
| deficient in lon and ompT proteases 
| general puropose expression host; expression induced by addition of arabinose 
| none
|-
| BL21 SI 
| deficient in lon and ompT proteases 
| general puropose expression host; expression induced by addition of NaCl 
| none
|-
| BL21 (DE3) 
| deficient in lon and ompT proteases 
| general puropose expression host 
| none
|-
| BL21 (DE3) cc1 
| deficient in lon and ompT proteases; contains plasmids&nbsp;encoding bacterial chaperones 
| general puropose expression host&nbsp;; allows expression of genes encoding DnaK, DnaJ and GrpE 
| Cam (10µg/ml) + Spec
|-
| BL21 (DE3) cc2 
| deficient in lon and ompT proteases; contains plasmids&nbsp;encoding bacterial chaperones 
| general puropose expression host&nbsp;; allows expression of genes encoding DnaK, DnaJ, GrpE and ClpB 
| Cam (10µg/ml) + Spec
|-
| BL21 (DE3) cc3 
| deficient in lon and ompT proteases; contains plasmids&nbsp;encoding bacterial chaperones 
| general puropose expression host&nbsp;; allows expression of genes encoding GroEL and GroES 
| Cam (10µg/ml) + Spec
|-
| BL21 (DE3) cc4 
| deficient in lon and ompT proteases; contains plasmids&nbsp;encoding bacterial chaperones 
| general puropose expression host&nbsp;; allows expression of genes encoding DnaK, DnaJ and GrpE, GroEL, GroES and ClpB 
| Cam (10µg/ml) + Spec
|-
| BL21 (DE3) cc5 
| deficient in lon and ompT proteases; contains plasmids&nbsp;encoding bacterial chaperones 
| general puropose expression host&nbsp;; allows expression of genes encoding DnaK, DnaJ and GrpE, GroEL (low), GroES (low)&nbsp;and ClpB 
| Cam (10µg/ml) + Spec
|-
| BL21 (DE3) pLysS 
| deficient in lon and ompT proteases 
| general puropose high-stringency expression host 
| Cam
|-
| BL21 (DE3) pLysE 
| deficient in lon and ompT proteases 
| general puropose high-stringency expression host 
| Cam
|-
| BL21 (DE3) CodonPlus-RIL 
| deficient in lon and ompT proteases; contains plasmid encoding argU, ileX and leuW. 
| exression host; allows expression of genes enpcoding tRNAs for rare argenine codon AGA and AGG, isoleucine codon AUA and leucine codon CUA 
| Cam
|-
| BL21 (DE3) CodonPlus-RP 
| deficient in lon and ompT proteases; contains plasmid encoding argU, and proL. 
| expression host; allows expression of genes encoding tRNAs for rare argenine codon AGA and AGG and proline codon CCC 
| Cam
|-
| BL21 Star (DE3) 
| RNaseE (rne131) mutant 
| general puropose expression host with reduced mRNA degradation 
| none
|-
| BL21 Star (DE3) pLysS 
| RNaseE (rne131) mutant 
| general puropose high-stringency expression host with reduced mRNA degradation 
| Cam
|-
| BL21 Star (DE3) pRARE 
| RNaseE (rne131) mutant; contains plasmid encoding&nbsp; argU, argW, glyT, ileX, leuW, metT, proL, thrT, thrU and&nbsp;tyrU. 
| general purpose expression host with reduced mRNA degradation; allows expression of genes encoding tRNAs for rare argenine codons AGA and AGG, glycine codon GGA, isoleucine codon AUA, leucine codon CUA,&nbsp;methionine codon AUG,&nbsp;proline codon CCC, threonine codons&nbsp;ACA and ACC, and tyrosine codon UAC 
| Cam
|-
| BL21 Star (DE3) pRARE2 
| RNaseE (rne131) mutant; contains plasmid encoding&nbsp; argU, argW, argX, glyT, ileX, leuW, metT, proL, thrT, thrU and&nbsp;tyrU. 
| general purpose expression host with reduced mRNA degradation; allows expression of genes encoding tRNAs for rare argenine codons AGA, AGG, CGA and CGG, glycine codon GGA, isoleucine codon AUA, leucine codon CUA,&nbsp;methionine codon AUG,&nbsp;proline codon CCC, threonine codons&nbsp;ACA and ACC, and tyrosine codon UAC 
| Cam
|-
| BLR (DE3) 
| recA- derivative of BL21 
| recA- expression host; recommended for use with tandem repeats 
| Tet
|-
| C41 (DE3) 
| deficient in lon and ompT proteases; ATPase mutant 
| host for expression of membrane proteins 
| none
|-
| C43 (DE3) 
| deficient in lon and ompT proteases; ATPase mutant 
| host for expression of membrane proteins 
| none
|-
| DB3.1 
| contains the gyrA462 allelle which renders the strain resistant to toxic effect of the ccdB gene 
| host for the propagation of GATEWAY vectors (containing the ccdB gene) 
| none
|-
| DH5α 
| 
| host for cloning and plasmid propagation 
| none
|-
| DH5α Pro/ pRK1037 
| contains plasmid (pRK1037) encoding gene for TVMV protease 
| expression host; allows expression of&nbsp; TVMV protease 
| Kan
|-
| DH10Bac 
| contains parent bacmid bMON14272 and helper plasmid pMON7124 
| host for the generation of recombinant bacmid DNA from pFastBac vectors&nbsp;for use in BEVS technology 
| Kan + Tet
|-
| DL41 (DE3) 
| methionine auxotroph 
| labeling of proteins with 35S-methionine and selenomethinine 
| none
|-
| HMS174 
| recA mutant 
| recA- expression host 
| Rif
|-
| HMS174 (DE3) 
| recA mutant 
| recA- expression host 
| Rif
|-
| HMS174 (DE3) pLysS 
| recA mutant 
| recA- high-stringency expression host 
| Rif + Cam
|-
| HMS174 (DE3) pLysE 
| recA mutant 
| recA- high-stringency expression host 
| Rif + Cam
|-
| JM101 
| 
| expression host (not with T7 promoter) 
| none
|-
| JM105 
| 
| expression host (not with T7 promoter) 
| none
|-
| JM 109 (DE3) 
| 
| expression host 
| none
|-
| JM110 
| dam and dcm mutant 
| dam and dcm expression host (not with T7 promoter); no methylation of DNA at dam and dcm sites 
| none
|-
| LMG194 
| ara mutant 
| expression host used in combination with vectors containing BAD promoter 
| none
|-
| M15 [pREP4] 
| contains helper plasmid pREP4 
| expression nused in combination with most pQE vectors (Qiagen) 
| Kan
|-
| NovaBlue 
| 
| host for cloning and plasmid propagation 
| none
|-
| Origami 
| trxB and gor mutant 
| expression host (not&nbsp;with T7 promoter); disulfite bond formation in cytoplasm 
| Kan
|-
| Origami (DE3) 
| trxB and gor mutant 
| expression host; disulfite bond formation in cytoplasm 
| Kan
|-
| Origami (DE3) pLysS 
| trxB and gor mutant 
| high-stringency expression host; disulfite bond formation in cytoplasm 
| Kan + Cam
|-
| Origami (DE3) pLacI 
| trxB and gor mutant 
| high-stringency expression host; disulfite bond formation in cytoplasm 
| Kan + Cam
|-
| Rosetta 
| lactose permease (lacY) mutant; protease deficient, contains plasmid encoding&nbsp; argU, argW, glyT, ileX, leuW, metT, proL, thrT, thrU &amp;&nbsp;tyrU. 
| expression host (not with T7 promoter);&nbsp;allows expression of genes encoding tRNAs for rare argenine codons AGA and AGG, glycine codon GGA, isoleucine codon AUA, leucine codon CUA,&nbsp;methionine codon AUG,&nbsp;proline codon CCC, threonine codons&nbsp;ACA and ACC, and tyrosine codon UAC 
| Cam
|-
| Rosetta (DE3) 
| lactose permease (lacY) mutant; protease deficient, contains plasmid encoding&nbsp; argU, argW, glyT, ileX, leuW, metT, proL, thrT, thrU &amp;&nbsp;tyrU. 
| expression host;&nbsp;allows expression of genes encoding tRNAs for rare argenine codons AGA and AGG, glycine codon GGA, isoleucine codon AUA, leucine codon CUA,&nbsp;methionine codon AUG,&nbsp;proline codon CCC, threonine codons&nbsp;ACA and ACC, and tyrosine codon UAC 
| Cam
|-
| Rosetta (DE3) pLysS 
| lactose permease (lacY) mutant; protease deficient, contains plasmid encoding&nbsp; argU, argW, glyT, ileX, leuW, metT, proL, thrT, thrU &amp;&nbsp;tyrU. 
| high-stringency expression host;&nbsp;allows expression of genes encoding tRNAs for rare argenine codons AGA and AGG, glycine codon GGA, isoleucine codon AUA, leucine codon CUA,&nbsp;methionine codon AUG,&nbsp;proline codon CCC, threonine codons&nbsp;ACA and ACC, and tyrosine codon UAC 
| Cam
|-
| Rosetta(DE3) pLacI 
| lactose permease (lacY) mutant; protease deficient, contains plasmid encoding&nbsp; argU, argW, glyT, ileX, leuW, metT, proL, thrT, thrU &amp;&nbsp;tyrU. 
| high-stringency expression host;&nbsp;allows expression of genes encoding tRNAs for rare argenine codons AGA and AGG, glycine codon GGA, isoleucine codon AUA, leucine codon CUA,&nbsp;methionine codon AUG,&nbsp;proline codon CCC, threonine codons&nbsp;ACA and ACC, and tyrosine codon UAC 
| Cam
|-
| Rosetta2 (DE3) 
| lactose permease (lacY) mutant; deficient in lon and ompT proteases; contains plasmid encoding&nbsp; argU, argW, argX, glyT, ileX, leuW, metT, proL, thrT, thrU and&nbsp;tyrU. 
| expression host; allows expression of genes encoding tRNAs for rare argenine codons AGA, AGG, CGA and CGG, glycine codon GGA, isoleucine codon AUA, leucine codon CUA,&nbsp;methionine codon AUG,&nbsp;proline codon CCC, threonine codons&nbsp;ACA and ACC, and tyrosine codon UAC 
| Cam
|-
| Rosetta2 (DE3) pLysS 
| lactose permease (lacY) mutant; deficient in lon and ompT proteases; contains plasmid encoding&nbsp; argU, argW, argX, glyT, ileX, leuW, metT, proL, thrT, thrU and&nbsp;tyrU. 
| high-stringency expression host; allows expression of genes encoding tRNAs for rare argenine codons AGA, AGG, CGA and CGG, glycine codon GGA, isoleucine codon AUA, leucine codon CUA,&nbsp;methionine codon AUG,&nbsp;proline codon CCC, threonine codons&nbsp;ACA and ACC, and tyrosine codon UAC 
| Cam
|-
| Rosetta-gami2 (DE3) 
| lactose permease (lacY) mutant; trxB and gor mutant; deficient in lon and ompT proteases; contains plasmid encoding argU, argW, argX, glyT, ileX, leuW, metT, proL, thrT, thrU and tyrU. 
| expression host; disulfite bond formation in cytoplasm; allows expression of genes encoding tRNAs for rare argenine codons AGA, AGG, CGA and CGG, glycine codon GGA, isoleucine codon AUA, leucine codon CUA,&nbsp;methionine codon AUG,&nbsp;proline codon CCC, threonine codons&nbsp;ACA and ACC, and tyrosine codon UAC 
| Cam
|-
| Rosetta-gami2 (DE3) pLysS 
| lactose permease (lacY) mutant; trxB and gor mutant; deficient in lon and ompT proteases; contains plasmid encoding argU, argW, argX, glyT, ileX, leuW, metT, proL, thrT, thrU and tyrU. 
| high-stringency expression host; disulfite bond formation in cytoplasm; allows expression of genes encoding tRNAs for rare argenine codons AGA, AGG, CGA and CGG, glycine codon GGA, isoleucine codon AUA, leucine codon CUA,&nbsp;methionine codon AUG,&nbsp;proline codon CCC, threonine codons&nbsp;ACA and ACC, and tyrosine codon UAC 
| Cam
|-
| TB1 
| 
| host for pUC plasmids 
| none
|-
| Top10 
| ara mutant 
| host for general purposse cloning and plasmid propagation, expression host used in combination with vectors containing BAD promoter 
| none
|-
| Tuner 
| lactose permease (lacY) mutant 
| expression host (not with T7 promoter);&nbsp;allows uniform uptake of IPTG 
| none
|-
| Tuner (DE3) 
| lactose permease (lacY) mutant 
| expression host;&nbsp;allows uniform uptake of IPTG 
| none
|-
| Tuner (DE3) pLysS 
| lactose permease (lacY) mutant 
| high-stringency expression host;&nbsp;allows uniform uptake of IPTG 
| Cam
|-
| Tuner (DE3) pLacI 
| lactose permease (lacY) mutant 
| high-stringency expression host;&nbsp;allows uniform uptake of IPTG 
| Cam
|-
| XL1-Blue 
| 
| host for cloning and plasmid propagation 
| Tet
|}

<br> 

{| border="1"
|-
| align="center" style="background:#f0f0f0;" | '''Strain''' 
| align="center" style="background:#f0f0f0;" | '''Description''' 
| align="center" style="background:#f0f0f0;" | '''Application'''
|-
| B834 (DE3) pRARE
| "methionine auxotroph;
|-
| deficient in lon and ompT proteases; contains plasmid encoding argU, argW, glyT, ileX, leuW, metT, proL, thrT, thrU &amp; tyrU."
| "high-stringency expression host;
|-
| labelling of proteins with 35S-methionine and selenomethionine; allows expression of genes encoding tRNAs for rare argenine codons AGA and AGG, glycine codon GGA, isoleucine codon AUA, leucine codon CUA, methionine codon AUG, proline codon CCC, threonine codons ACA and ACC, and tyrosine codon UAC"
|-
| BB7333
| deficient in clpX, clpP and lon proteases
| general prupose expression host with inhibited protein degradation
|-
| BL21
| deficient in lon and ompT proteases
| general puropose expression host for plasmids which do not use a T7 promoter
|-
| BL21 AI
| deficient in lon and ompT proteases
| general puropose expression host; expression induced by addition of arabinose
|-
| BL21 SI
| deficient in lon and ompT proteases
| general puropose expression host; expression induced by addition of NaCl
|-
| BL21 (DE3)
| deficient in lon and ompT proteases
| general puropose expression host
|-
| BL21 (DE3) pKJE7
| deficient in lon and ompT proteases; contains plasmids encoding bacterial chaperones
| general puropose expression host&nbsp;; allows expression of genes encoding DnaK, DnaJ and GrpE; L-Arabinose
|-
| BL21 (DE3) pG-KJE8
| deficient in lon and ompT proteases; contains plasmids encoding bacterial chaperones
| "general puropose expression host&nbsp;; allows expression of genes encoding dnaK-dnaJ-grpE (L-Arabinose), GroES-groEL (Tetracyclin)
|-
| BL21 (DE3) pGro7
| deficient in lon and ompT proteases; contains plasmids encoding bacterial chaperones
| "general puropose expression host&nbsp;; allows expression of genes encoding groES-groEL (L-Arabinose )
|-
| BL21 (DE3) pG-Tf2
| deficient in lon and ompT proteases; contains plasmids encoding bacterial chaperones
| general puropose expression host&nbsp;; allows expression of genes encoding groES-groEL-tig (Tetracyclin )
|-
| BL21 (DE3) pTf16
| deficient in lon and ompT proteases; contains plasmids encoding bacterial chaperones
| "general puropose expression host&nbsp;; allows expression of genes encoding tig (L-Arabinose )
|-
| BL21 (DE3) pLysS
| deficient in lon and ompT proteases
| general puropose high-stringency expression host
|-
| BL21 (DE3) pLysE
| deficient in lon and ompT proteases
| general puropose high-stringency expression host
|-
| BL21 (DE3) CodonPlus-RIL
| deficient in lon and ompT proteases; contains plasmid encoding argU, ileX and leuW.
| exression host; allows expression of genes enpcoding tRNAs for rare argenine codon AGA and AGG, isoleucine codon AUA and leucine codon CUA
|-
| BL21 (DE3) CodonPlus-RP
| deficient in lon and ompT proteases; contains plasmid encoding argU, and proL.
| expression host; allows expression of genes encoding tRNAs for rare argenine codon AGA and AGG and proline codon CCC
|-
| BL21 Star (DE3)
| RNaseE (rne131) mutant
| general puropose expression host with reduced mRNA degradation
|-
| BL21 Star (DE3) pLysS
| RNaseE (rne131) mutant
| general puropose high-stringency expression host with reduced mRNA degradation
|-
| BL21 Star (DE3) pRARE
| RNaseE (rne131) mutant; contains plasmid encoding argU, argW, glyT, ileX, leuW, metT, proL, thrT, thrU and tyrU.
| general purpose expression host with reduced mRNA degradation; allows expression of genes encoding tRNAs for rare argenine codons AGA and AGG, glycine codon GGA, isoleucine codon AUA, leucine codon CUA, methionine codon AUG, proline codon CCC, threonine codons ACA and ACC, and tyrosine codon UAC
|-
| BL21 Star (DE3) pRARE2
| RNaseE (rne131) mutant; contains plasmid encoding argU, argW, argX, glyT, ileX, leuW, metT, proL, thrT, thrU and tyrU.
| general purpose expression host with reduced mRNA degradation; allows expression of genes encoding tRNAs for rare argenine codons AGA, AGG, CGA and CGG, glycine codon GGA, isoleucine codon AUA, leucine codon CUA, methionine codon AUG, proline codon CCC, threonine codons ACA and ACC, and tyrosine codon UAC
|-
| BLR (DE3)
| recA- derivative of BL21
| recA- expression host; recommended for use with tandem repeats
|-
| C41 (DE3)
| deficient in lon and ompT proteases; ATPase mutant
| host for expression of membrane proteins
|-
| C43 (DE3)
| deficient in lon and ompT proteases; ATPase mutant
| host for expression of membrane proteins
|-
| DH5α
| 
| host for cloning and plasmid propagation
|-
| DH5α Pro/ pRK1037
| contains plasmid (pRK1037) encoding gene for TVMV protease
| expression host; allows expression of TVMV protease
|-
| DH10Bac
| contains parent bacmid bMON14272 and helper plasmid pMON7124
| host for the generation of recombinant bacmid DNA from pFastBac vectors for use in BEVS technology
|-
| JM 109 (DE3)
| 
| expression host
|-
| JM110
| dam and dcm mutant
| dam and dcm expression host (not with T7 promoter); no methylation of DNA at dam and dcm sites
|-
| LMG194
| ara mutant
| expression host used in combination with vectors containing BAD promoter
|-
| M15 [pREP4]
| contains helper plasmid pREP4
| expression nused in combination with most pQE vectors (Qiagen)
|-
| NovaBlue
| 
| host for cloning and plasmid propagation
|-
| Origami
| trxB and gor mutant
| expression host (not with T7 promoter); disulfite bond formation in cytoplasm
|-
| Origami (DE3)
| trxB and gor mutant
| expression host; disulfite bond formation in cytoplasm
|-
| Origami (DE3) pLysS
| trxB and gor mutant
| high-stringency expression host; disulfite bond formation in cytoplasm
|-
| Origami (DE3) pLacI
| trxB and gor mutant
| high-stringency expression host; disulfite bond formation in cytoplasm
|-
| Rosetta
| lactose permease (lacY) mutant; protease deficient, contains plasmid encoding argU, argW, glyT, ileX, leuW, metT, proL, thrT, thrU &amp; tyrU.
| expression host (not with T7 promoter); allows expression of genes encoding tRNAs for rare argenine codons AGA and AGG, glycine codon GGA, isoleucine codon AUA, leucine codon CUA, methionine codon AUG, proline codon CCC, threonine codons ACA and ACC, and tyrosine codon UAC
|-
| Rosetta (DE3)
| lactose permease (lacY) mutant; protease deficient, contains plasmid encoding argU, argW, glyT, ileX, leuW, metT, proL, thrT, thrU &amp; tyrU.
| expression host; allows expression of genes encoding tRNAs for rare argenine codons AGA and AGG, glycine codon GGA, isoleucine codon AUA, leucine codon CUA, methionine codon AUG, proline codon CCC, threonine codons ACA and ACC, and tyrosine codon UAC
|-
| Rosetta (DE3) pLysS
| lactose permease (lacY) mutant; protease deficient, contains plasmid encoding argU, argW, glyT, ileX, leuW, metT, proL, thrT, thrU &amp; tyrU.
| high-stringency expression host; allows expression of genes encoding tRNAs for rare argenine codons AGA and AGG, glycine codon GGA, isoleucine codon AUA, leucine codon CUA, methionine codon AUG, proline codon CCC, threonine codons ACA and ACC, and tyrosine codon UAC
|-
| Rosetta(DE3) pLacI
| lactose permease (lacY) mutant; protease deficient, contains plasmid encoding argU, argW, glyT, ileX, leuW, metT, proL, thrT, thrU &amp; tyrU.
| high-stringency expression host; allows expression of genes encoding tRNAs for rare argenine codons AGA and AGG, glycine codon GGA, isoleucine codon AUA, leucine codon CUA, methionine codon AUG, proline codon CCC, threonine codons ACA and ACC, and tyrosine codon UAC
|-
| Rosetta2 (DE3)
| lactose permease (lacY) mutant; deficient in lon and ompT proteases; contains plasmid encoding argU, argW, argX, glyT, ileX, leuW, metT, proL, thrT, thrU and tyrU.
| expression host; allows expression of genes encoding tRNAs for rare argenine codons AGA, AGG, CGA and CGG, glycine codon GGA, isoleucine codon AUA, leucine codon CUA, methionine codon AUG, proline codon CCC, threonine codons ACA and ACC, and tyrosine codon UAC
|-
| Rosetta2 (DE3) pLysS
| lactose permease (lacY) mutant; deficient in lon and ompT proteases; contains plasmid encoding argU, argW, argX, glyT, ileX, leuW, metT, proL, thrT, thrU and tyrU.
| high-stringency expression host; allows expression of genes encoding tRNAs for rare argenine codons AGA, AGG, CGA and CGG, glycine codon GGA, isoleucine codon AUA, leucine codon CUA, methionine codon AUG, proline codon CCC, threonine codons ACA and ACC, and tyrosine codon UAC
|-
| Rosetta-gami2 (DE3)
| lactose permease (lacY) mutant; trxB and gor mutant; deficient in lon and ompT proteases; contains plasmid encoding argU, argW, argX, glyT, ileX, leuW, metT, proL, thrT, thrU and tyrU.
| expression host; disulfite bond formation in cytoplasm; allows expression of genes encoding tRNAs for rare argenine codons AGA, AGG, CGA and CGG, glycine codon GGA, isoleucine codon AUA, leucine codon CUA, methionine codon AUG, proline codon CCC, threonine codons ACA and ACC, and tyrosine codon UAC
|-
| Rosetta-gami2 (DE3) pLysS
| lactose permease (lacY) mutant; trxB and gor mutant; deficient in lon and ompT proteases; contains plasmid encoding argU, argW, argX, glyT, ileX, leuW, metT, proL, thrT, thrU and tyrU.
| high-stringency expression host; disulfite bond formation in cytoplasm; allows expression of genes encoding tRNAs for rare argenine codons AGA, AGG, CGA and CGG, glycine codon GGA, isoleucine codon AUA, leucine codon CUA, methionine codon AUG, proline codon CCC, threonine codons ACA and ACC, and tyrosine codon UAC
|-
| TB1
| 
| host for pUC plasmids
|-
| Top10
| ara mutant
| host for general purposse cloning and plasmid propagation, expression host used in combination with vectors containing BAD promoter
|-
| Tuner
| lactose permease (lacY) mutant
| expression host (not with T7 promoter); allows uniform uptake of IPTG
|-
| Tuner (DE3)
| lactose permease (lacY) mutant
| expression host; allows uniform uptake of IPTG
|-
| Tuner (DE3) pLysS
| lactose permease (lacY) mutant
| high-stringency expression host; allows uniform uptake of IPTG
|-
| Tuner (DE3) pLacI
| lactose permease (lacY) mutant
| high-stringency expression host; allows uniform uptake of IPTG
|-
| XL1-Blue
| 
| host for cloning and plasmid propagation
|-
| 
|}

[[Category:Competent_Cells]] [[Category:Protocols]]