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  • T7 Express High Efficiency Sampler

    Description

    A sample pack of four T7 strains of E. Coli suitable for high efficiency transformation and protein expression.

    Highlights

    • Transformation efficiency: 0.6-1 x 109 cfu/µg pUC19 DNA
    • T7 RNA Polymerase in the lac operon - no lambda prophage
    • Tight control of expression by lacIq allow potentially toxic genes to be cloned
    • Control of T7 RNA Polymerase by mutant lysozyme (LysY) allows toxic genes to be expressed
    • LysY is a variant of T7 lysozyme lacking amidase activity, thus cells are less susceptible to lysis during induction
    • Maintenance of lysozyme plasmid does not require antibiotic selection
    • Deficient in proteases Lon and OmpT
    • Resistant to phage T1 (fhuA2)
    • Does not restrict methylated DNA (McrA-, McrBC-, EcoBr-m-, Mrr-)
    • B Strain

    Reagents Supplied

    The following reagents are supplied with this product:

    Store at (°C)Concentration
    pUC19 Transformation Control Plasmid-200.05 ng/μl
    SOC Outgrowth Medium41X
    T7 Express Competent E. coli (High Efficiency)-802X
    T7 Express lysY Competent E. coli (High Efficiency)-802X
    T7 Express lysY/Iq Competent E. coli (High Efficiency)-802X
    T7 Express Iq Competent E. coli (High Efficiency)-802X

    Advantages and Features

    Features

    • T7 expression
    • Protease deficient

    Applications


    Transformation of a toxic mammalian clone into E. coli hosts. A T7 expression plasmid and the same plasmid containing a gene encoding a toxic mammalian protein were transformed into each host. Comparison of the relative transformation efficiencies demonstrates that the T7 Express hosts provide the levels of control necessary for transformation of potentially toxic clones. BL21(DE3) could not be transformed with the toxic clone.

    T7-controlled expression of a non-toxic protein in E. coli hosts. A T7 expression plasmid containing a gene encoding an E. coli protein was transformed into each host, grown to 0.6 OD and induced for 3 hours. Comparison of soluble extracts from uninduced (-) and induced (+) cells shows superior control of expression in the T7 Express hosts while maintaining high levels of induced expression.
    Transformation of a toxic mammalian clone into E. coli hosts. A T7 expression plasmid and the same plasmid containing a gene encoding a toxic mammalian protein were transformed into each host. Comparison of the relative transformation efficiencies demonstrates that the T7 Express hosts provide the levels of control necessary for transformation of potentially toxic clones. BL21(DE3) could not be transformed with the toxic clone.

    T7-controlled expression of a non-toxic protein in E. coli hosts. A T7 expression plasmid containing a gene encoding an E. coli protein was transformed into each host, grown to 0.6 OD and induced for 3 hours. Comparison of soluble extracts from uninduced (-) and induced (+) cells shows superior control of expression in the T7 Express hosts while maintaining high levels of induced expression.

    Properties and Usage

    Antibiotics for Plasmid SelectionWorking Concentration
    Ampicillin100 μg/ml
    Carbenicillin100 μg/ml
    Kanamycin30 μg/ml
    Streptomycin25 μg/ml
    Tetracycline15 μg/ml

    Storage Temperature

    -80°C

    Shipping Notes

    • Ships on dry ice

    Quality Control

    Quality Control Assays

    The following Quality Control Tests are performed on each new lot and meet the specifications designated for the product. Individual lot data can be found on the Product Summary Sheet/Datacard or Manual which can be found in the Supporting Documents section of this page.
    • Transformation Efficiency:
      The competent cells are tested for transformation efficiency and pass minimum release criteria. Transformation efficiency is defined as the number of colony forming units (cfu) which would be produced by transforming 1 μg of plasmid into a given volume of competent cells.

    Supporting Documents

    Material Safety Datasheets

    The following is a list of Material Safety Data Sheets (MSDS) that apply to this product to help you use it safely. The following file naming structure is used to name these document files: [Product Name] MSDS. For international versions please contact us at info@neb.com.

    Datacards

    The Product Summary Sheet, or Data Card, includes details for how to use the product, as well as details of its formulation and quality controls. The following file naming structure is used to name the majority of these document files: [Catalog Number]Datasheet-Lot[Lot Number]. For those product lots not listed below, please contact NEB at info@neb.com or fill out the Technical Support Form for appropriate document.
    1. Why are there no colonies or no growth in liquid culture (C3009)?
    2. Why is there no protein visible on gel or no activity (C3009)?
    3. Why is induced protein insoluble (C3009)?
    4. What are the solutions/recipes (C3009)?
    5. Can I store competent cells at -20°C instead of -80°C?
    6. What are the strain properties (C3009)?
    7. Which kind of transformation tubes should be used?
    8. What volume of DNA can be added into competent cells?
    9. What is the shelf life for this strain (NEB #C3009I)?
    10. Are NEB's competent cells compatible with the "Plate and Go" protocol?
    1. 5 Minute Transformation Protocol (C3009)
    2. Protocol for Expression Using T7 Express Sampler (C3009)
    3. High Efficiency Transformation Protocol (C3009)

    Selection Tools

    Usage Guidelines & Tips

    Application Notes