The E. coli competent cells, prepared according to a modified procedure of Hanahan, can be used for many standard molecular biology applications.
- Cells are ready to use, no preparation time necessary
- Transformation efficiencies guaranteed
- No undesirable recombination events
JM109 competent cells are available for convenient transformation in two efficiencies: High Efficiency at greater than 108 cfu/µg and Subcloning Efficiency at greater than 107 cfu/µg. HB101 competent cells are available in high efficiency at greater than 108 cfu/µg. JM109 cells are ideal hosts for many molecular biology applications, including blue/white screening.
HB101 cells are useful for cloning in vectors that do not require a-complementation for blue/white screening.
BL21(DE3)pLysS cells can be used with protein expression vectors that are under the control of the T7 promoter, such as pET vectors. This strain is lysogenic for lambda-DE3, which contains the T7 bacteriophage gene 1, encoding T7 RNA polymerase under the control of the lacUV5 promoter. BL21(DE3)pLysS also contains the pLysS plasmid, which carries the gene encoding T7 lysozyme. T7 lysozyme lowers the background expression level of target genes under the control of the T7 promoter but does not interfere with the level of expression achieved following induction with IPTG.
Fornecimento: Competent cells, supplied in 200 µl aliquots, are provided with 3 ng of competent cells control DNA for use as a positive control. Typically, 100 µl of competent cells are required for a standard transformation. Competent cells supplied in 50 µl aliquots do not include the control DNA. For the competent cells supplied in 50 µl aliquots, transformation can be completed in the tube in which the cells are supplied.
