Bacteria
E. coli BL21(DE) Ril
Strain/Type
E. coli B-derived strain
Genotype: E. coli str. B F– ompT gal dcm lon hsdSB(rB–mB–) λ(DE3 [lacI lacUV5-T7p07 ind1 sam7 nin5]) [malB+]K-12(λS)
Characteristics e.g. sensitizing or toxic effects, resistance to antibiotics
Chloramphenicol resistance, E. coli B F– ompT hsdS(rB– mB–) dcm+ Tetr gal λ(DE3) endA Hte [argU ileY leuW Camr]
Approved as biological safety measure if taken as recipient organism for genetic engineering?
no
Genetically modified (GenTSV)
yes (S1): E. coli B F– ompT hsdS(rB– mB–) dcm+ Tetr gal λ(DE3) endA Hte [argU ileY leuW Camr] → S1
Risk group (BioStoffV)
1
Risk assessment
Storage location of aliquots in the Biolab (just click Bearbeiten in the right corner of the header to add or change information in the table and use the menue in the left header to e.g. add a row)
| source | bacterial strain | freezing date | amount of bacteria per vial | stock was produced on | no. of aliquots | belongs to (full name) | rack/box in N2 tank or -80°C freezer and location (room, address) | comments |
|---|---|---|---|---|---|---|---|---|
| Wahl Group | 03.11.21 | 100 µL | ZymoBroth | 15 | Robyn Diehn (AG Lauster) | B6 -80 °C -80°C "Omega", 115.2? | ||
Background
Bacteria for heterologous protein production → has additional tRNAs for rare E. coli codons: Arg (AGG/AGA), Ile (AUA) and Leu (CUA).
If your gene of interest comes from a species with a very different codon usage than E. coli, this can lead to very low expression levels. Using this strain can help with this issue.
The strain contains DE3, a λ prophage carrying the T7 RNA polymerase gene under control of the lac UV5 promoter and lacIq. IPTG is required to induce expression of the T7 RNA polymerase. Protein expression from transforming plasmids containing a T7 promoter-driven expression system is repressed until IPTG induction of T7 RNA polymerase expression occurs. The strain does not contain the lon protease and is also deficient in the outer membrane protease, OmpT. The lack of two key proteases reduces the degradation of heterologous proteinsexpressed in the strain.
Cultivation and freezing protocols
