Editing Invitrogen Competent Cells

{| width="100%" cellspacing="0"
|-
! valign="top" | Product Name 
! valign="top" | Genotype
|-
| valign="top" | 
BL21-AI™

| valign="top" | 
F– ompT hsdSB(rB–, mB–) gal dcm araB::T7RNAP-tetA 

|-
| valign="top" | 
BL21(DE3)

| valign="top" | 
F– ompT hsdSB(rB–, mB–) gal dcm (DE3) 

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| valign="top" | 
BL21(DE3)pLysS 

| valign="top" | 
F– ompT hsdSB(rB–, mB–) gal dcm (DE3) pLysS (CamR) 

|-
| valign="top" | 
BL21(DE3)pLysE&nbsp;

| valign="top" | 
F– ompT hsdSB(rB–, mB–) gal dcm (DE3) pLysE (CamR)

|-
| valign="top" | 
BL21 Star™(DE3)&nbsp;

| valign="top" | 
F– ompT hsdSB(rB–, mB–) gal dcm rne131 (DE3)

|-
| valign="top" | 
BL21 Star™ (DE3)pLysS

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F– ompT hsdSB(rB–, mB–) gal dcm rne131 (DE3) pLysS (CamR) 

|}
<div></div><div><br>
{| cellspacing="0" cellpadding="0" border="0"
|-
! Sku 
! Product Catalog 
! Size 
! Price
|-
| A11154 
| PichiaPink™ Expression Strain Set 
| 4 × 1ml<br> 
| id="price1" | 1,067.31 USD<br>
|-
| C6000-03 
| One Shot® BL21(DE3) Chemically Competent E. coli 
| 20 × 50 µl<br> 
| id="price2" | 253.26 USD<br>
|-
| C6010-03 
| One Shot® BL21 Star™ (DE3) Chemically Competent E. coli 
| 20 reactions<br> 
| id="price3" | 331.65 USD<br>
|-
| C6020-03 
| BL21 Star™ (DE3)pLysS One Shot® Chemically Competent E. 
coli 

| 20 × 50 µl<br> 
| id="price4" | 334.67 USD<br>
|-
| C6060-03 
| One Shot® BL21(DE3)pLysS Chemically Competent E. coli 
| 20 × 50 µl<br> 
| id="price5" | 281.40 USD<br>
|-
| C6060-10 
| One Shot® BL21(DE3)pLysS Chemically Competent E. coli 
| 10 × 50 µl<br> 
| id="price6" | 165.83 USD<br>
|-
| C6070-03 
| BL21-AI™ One Shot® Chemically Competent E. coli 
| 20 × 50 µl<br> 
| id="price7" | 322.61 USD<br>
|-
| C6565-03 
| One Shot® BL21(DE3)pLysE Chemically Competent E. coli 
| 20 × 50 µl<br> 
| id="price8" | 258.29 USD<br>
|- id="addButton_9950"
| colspan="5" | <br>
|}
<br></div>
== Genotypes ==

{| width="100%" cellspacing="0" align="" summary=""
|-
! valign="top" | Genotype 
! valign="top" | Description
|-
| width="100" | 
ara-14&nbsp;

| 
Blocks arabinose catabolism&nbsp;

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| width="100" | 
argF&nbsp;

| 
Ornithine carbamoyltransferase mutation blocks ability to use arginine&nbsp;

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dam/dcm&nbsp;

| 
Abolishes endogenous adenine methylation at GATC sequences 

(dam) or cytosine methylation at CCWGG sequences (dcm). Used to propagate DNA for cleavage with certain restriction enzymes (e.g. Ava 
II, Bcl I)&nbsp;


|-
| width="100" | 
DE3&nbsp;

| 
Lysogen that encodes T7 RNA polymerase. Used to induce expression in T7-driven expression systems&nbsp;

|-
| width="100" | 
endA&nbsp;

| 
endA Mutation in the non-specific endonuclease Endonuclease I; 

eliminates non-specific endonuclease activity, resulting in improved 
plasmid preps&nbsp;


|-
| width="100" | 
F´ &nbsp;

| 
A self-transmissible, low-copy plasmid used for the generation 

of single-stranded DNA when infected with M13 phage; may contain a resistance marker to allow maintenance and will often carry the lacI 
and lacZ∆M15 genotypes&nbsp;


|-
| width="100" | 
galK&nbsp;

| 
Galactokinase mutation blocks catabolism of galactose—cells 

that are galK minus grow in the presence of galactose as the sole 
carbon source&nbsp;


|-
| width="100" | 
galU&nbsp;

| 
Glucose-1-phosphate uridylyltransferase mutation blocks 

ability to use galactose—cells that are galU minus can grow on media 
that contains galactose as the sole carbon source&nbsp;


|-
| width="100" | 
gyrA96 &nbsp;

| 
DNA gyrase mutant produces resistance to nalidixic acid&nbsp;

|-
| width="100" | 
hsd &nbsp;

| 
Mutations in the system of methylation and restriction that 

allow E. coli to recognize DNA as foreign. The hsd genotype allows efficient transformation of DNA generated from PCR reactions 

*hsdR–eliminates restriction of unmethylated EcoK I sites. (1) 
**hs&nbsp;



|-
| width="100" | 
lacI &nbsp;

| 
Encodes the lac repressor that controls expression from 

promoters that carry the lac operator; IPTG binds the lac repressor and derepresses the promoter; often used when performing blue/white 
screening or to control expression of recombinant genes&nbsp;


|-
| width="100" | 
lacY1 &nbsp;

| 
Blocks use of lactose via β-D-galactosidase mutant&nbsp;

|-
| width="100" | 
lacZ &nbsp;

| 
β-D-galactosidase gene; mutations yield colorless (vs. blue) colonies in the presence of X-gal&nbsp;

|-
| width="100" | 
lacZ∆M15 &nbsp;

| 
Element required for β-galactosidase complementation when 

plated on X-gal; used in blue/white screening of recombinants; usually 
carried on the lambdoid prophage φ80 or F´&nbsp;


|-
| width="100" | 
leuB &nbsp;

| 
Requires leucine for growth on minimal media via β-isopropyl malate dehydrogenase mutation&nbsp;

|-
| width="100" | 
lon &nbsp;

| 
lon Deficiency in the Lon ATPase-dependent protease; decreases 

the degradation of recombinant proteins; all B strains carry this 
mutation&nbsp;


|-
| width="100" | 
mcrA, mcrBC,or mrr&nbsp;

| 
Mutations that allow methylated DNA to not be recognized as 

foreign; this genotype is necessary when cloning genomic DNA or 
methylated cDNA &nbsp;


|-
| width="100" | 
nupG &nbsp;

| 
Mutation for the transport of nucleosides&nbsp;

|-
| width="100" | 
ompT &nbsp;

| 
Indicates that the E. coli lack an outer membrane 

protease—reduces degradation of heterologous the strains and recovery 
of intact recombinant proteins is improved in ompT minus strains&nbsp;


|-
| width="100" | 
P3 &nbsp;

| 
A 60-kb low-copy plasmid that carries the ampicillin and 

tetracycline resistance genes with amber mutations; used predominantly for selection of supF-containing plasmids; carries the kanamycin 
resistance gene for selection&nbsp;


|-
| width="100" | 
pLys &nbsp;

| 
pLys Plasmid that encodes T7 lysozyme; used to reduce basal 

expression in T7-driven expression systems by inhibiting basal levels 
of T7 RNA polymerase&nbsp;


|-
| width="100" | 
proAB &nbsp;

| 
proAB Requires proline for growth on minimal media&nbsp;

|-
| width="100" | 
recA &nbsp;

| 
Mutation in a gene responsible for general recombination of DNA; particularly desirable when cloning genes with direct repeats&nbsp;

|-
| width="100" | 
relA &nbsp;

| 
RNA is synthesized in absence of protein synthesis (relaxed 

phenotype) relA locus regulates the coupling between transcription and translation. In the wild type, limiting amino acid concentrations 
results in the shutdown of RNA synthesis (also known as th&nbsp;


|-
| width="100" | 
rpsL&nbsp;

| 
Confers resistance to streptomycin (this makes a mutant ribosomal protein, small subunit, the target of the drug)&nbsp;

|-
| width="100" | 
supE,F&nbsp;

| 
tRNA glutamine suppressor of amber (supE)(UAG) or tyrosine (supF)&nbsp;

|-
| width="100" | 
thi-1 &nbsp;

| 
Requires thiamine for growth on minimal media&nbsp;

|-
| width="100" | 
Tn10 &nbsp;

| 
Confers tetracycline resistance via a transposon&nbsp;

|-
| width="100" | 
tonA&nbsp;

| 
Confers resistance to the lytic bacteriophage T1, T5 and f80&nbsp;

|-
| width="100" | 
traD, D36 &nbsp;

| 
Prevents transfer of F' episome via transfer factor mutation&nbsp;

|-
| width="100" | 
tsx &nbsp;

| 
Confers resistance to phage T6 and colicin K&nbsp;

|-
| width="100" | 
xyl-5 &nbsp;

| 
Blocks catabolism of xylose&nbsp;

|}

[[Category:Knowledgebase]]