The proprietary SE1 bacterial strain is recommended for protein expression when using StabyExpress, CherryExpress, StabyCodon or CherryCodon application.
This strain was derived from E. coli BL21(DE3) strain. SE1 is an expression strain allowing for the use of the T7 expression system. The gene encoding the T7 RNA polymerase is inserted into the chromosome of the expression bacteria. The protein expression is repressed by lacI and induced by the addition of IPTG into the culture medium or using an auto-inducible medium as StabyTMSwitch. Additionaly, the SE1 bacteria contain the ccdB selection gene in its chromosome allowing for the perfect plasmid stabilization (even without antibiotics) and consequently higher yields of expressed proteins.
The genotype of the SE1 strain is: F-, CmR, ompT, lon, hsdSB (restriction-, modification-), gal, dcm, DE3 (lacI, T7polymerase under the control of the PlacUV5 promoter), ccdB+.
CYS22 is a proprietary E. coli strain that contains the selection gene (ccdB) in its chromosome. This strain is recommended for cloning applications when using the StabyTM system. In CYS22 bacteria, plasmids encoding a ccdA gene are selected and perfectly stabilized even without antibiotics: 100% of bacteria contain the plasmid.
The CYS22 strain is recommended for cloning applications when using StabyCloning, StabyExpress, CherryExpress, StabyCodon, CherryCodon and GetStaby. This strain was derived from standard E. coli K12 cloning strain. It contains the ccdB selection gene in its chromosome allowing plasmid stabilization and selection of recombinants. This selection system is an antibiotic-free system.
The genotype of the CYS22 strain is: F-, endA1, glnV44, thi-1, recA1, relA1, gyrA96, nupG, dcm, hsdR17 (restriction-, modification+), Φ80lacZΔM15, Δ(lacZYA-argF)U169, λ-, ccdB+.
BL21(DE3) is the most widely host used for protein expression using E. coli and T7 expression system.
BL21(DE3) bacteria are convenient for protein expression using the T7 promoter. The (DE3) designation indicates that the host is a lysogen of lambda prophage (DE3), and therefore carries a chromosomal copy of the T7 RNA polymerase gene under control of the lacUV5 promoter (inducible by addition of IPTG or using the StabyTMSwitch auto-inducible medium). BL21(DE3) is the most widely used host for protein expression because it is deficient in the Lon and OmpT proteases.
BL21(DE3) bacteria are compatible with the StabyTMSwitch auto-inducible medium (without IPTG).
BL21(DE3) genotype : F- ompT lon hsdSB (rB-mB-) gal dcm (DE3)
DG1 Competent cells. Affordable chemically-competent E. coli bacteria in a convenient format for DNA cloning, library construction, plasmid amplification.
High-efficiency competent DG1 E. coli cells are supplied in a 96-tube tray (50µl of competent bacteria in each tube). This convenient format gives you the freedom to perform from 1 to 96 transformations at a time, without thawing more tubes of cells than needed. You can remove individual tubes by cutting cap strips. Thus, this format eliminates the reduced efficiencies that occur as a result of repeated freezing and thawing and makes possible high-throughput transformation. Racks feature 8 x 12 holes pattern for rapid processing using multi-channel pipettors. Alpha-numeric, non-reversing, rack and lid ensure positive sample ID.
DG1 E. coli cells are offered in the 24, 48 and 96 formats, chemically-competent, so you can pick the one that best suits the needs of your experiment. The competent E. coli bacteria are consistently high quality, with high efficiencies (>1x109 cfu/µg monomer plasmid DNA). The competent bacteria come complete with SOC media. Each tube contains 50µl of competent E. coli, which is sufficient for one high efficiency transformation.
DG1 is convenient for use in cloning, plasmid preparation and library construction. It is endonuclease and recombination minus. It allows lacZalpha complementation for blue/white screening.
DG1 electro-competent bacteria are available on request.
DG1: mcrA D(mrr-hsdRMS-mcrBC, modification-, restriction-) F80lacZDM15 DlacX74 recA1 araD139 D(ara-leu)7697 galU galK rpsL endA1 nupG
- Freedom to use anywhere from 1-96 reactions
- No wasted reactions
- High efficiency (>109 cfu/µg)
- Economical pricing
- Convenient for high-throughput use