Search Thermo Fisher Scientific
Search Thermo Fisher Scientific
產品號碼 | Quantity |
---|---|
C854003 | 21 x 50 μL/tube |
The One Shot OmniMAX 2 T1R E. coli strain is an improved chemically competent cell line that can achieve extremely high transformation efficiency of >5 x 109 transformants/μg pUC19 DNA. It offers the highest transformation efficiency of any chemically competent cells in a One Shot format. OmniMAX 2 T1R is a versatile strain, perfect to use in all cloning applications, including Gateway technology and TOPO PCR cloning.
OmniMAX 2 T1R Chemically Competent E. coli cells carry the tonA (also known as fhuA) mutation, which confers resistance to T1 and T5 phage infection. The tonA genotype offers added security to valuable clones and libraries. This strain lacks the E. coli K12 restriction systems (mcrA Δ(mrr hsdRMS-mcrBC)), allowing efficient transformation of highly methylated DNA. The OmniMAX 2 T1R strain has the lacZΔM15 genotype, allowing blue-white screening on plates containing either X-Gal or Bluo-Gal. It also carries the recA1 mutation, which helps reduce the rate of recombination while propagating plasmid DNA, and the endA1 mutation that increases plasmid DNA yield and quantity. The OmniMAX 2 T1R strain contains an F´ episome that can support cloning plasmids with an f1-like origin of replication (phagemids). In addition, the F´ episome carries the lacIq repressor for inducible expression from trc, tac, and lac promoters using IPTG. Importantly, the ccdA gene present on the F´ episome is deleted, allowing negative selection of Gateway vectors as the strain is sensitive to the ccdB gene product.
One Shot OmniMAX 2 T1R Chemically Competent E. coli offer:
• Highest transformation efficiencies of >5 x 109 cfu/μg
• tonA (fhuA) genotype to confer resistance to T1 and T5 phage
• Δ(ccdAB) for sensitivity to the toxic effects of the ccdB gene product, allowing negative selection of vectors containing the ccdB gene (Gateway cloning system)
• Stable F´ episome that carries lacIq repressor for inducible expression from trc, tac, and lac promoters
• Construction of more representative genomic libraries due to the elimination of mcrA, mcrBC, mrr, and hsdRMS
• lacZΔM15 for blue-white color screening of recombinant clones
• endA1 for cleaner DNA preparations and better results in downstream applications due to elimination of nonspecific digestion by Endonuclease I
• recA1 for reduced occurrence of nonspecific recombination in cloned DNA
Easy-to-use One Shot format
OmniMAX 2 T1R Chemically Competent E. coli cells are supplied in the convenient, single-reaction One Shot format. The single-tube, single-use format allows all steps of the transformation protocol, up to plating, to take place in the same tube, thereby helping save time and prevent contamination.
Genotype
F´ [proAB+lacIqlacZΔM15 Tn10(TetR) Δ(ccdAB)] mcrA Δ(mrr-hsdRMS-mcrBC) φ80lacZΔM15 Δ(lacZYA-argF)U169 endA1 recA1 supE44 thi-1 gyrA96 (NalR) relA1 tonA panD
Find the strain and format that fit your needs
We offer other strains in chemically competent and electrocompetent cell formats to meet your specific needs.
OmniMAX 2 T1R and other strains are available in MultiShot formats for high throughput applications.
Explore bacterial growth media formats.
See how these mediums can help with critical aspects of cloning!
Invitrogen One Shot LB Agar* ›
*Only available in North America and selected European countries
OmniMAX 2 is the preferred strain for transforming libraries because of its high transformation efficiency and genomic cloning compatibility characteristics.
There are other strains available that may function similarly to Stbl2 cells in stabilizing inserts or vectors with repeated DNA sequences. However, one advantage of Stbl2 cells over many similar strains is that they are sensitive to Kanamycin, so you can use Stbl2 to propagate plasmids containing a Kanamycin resistance marker.
For best results, DNA used in electroporation must have a very low ionic strength and a high resistance. A high-salt DNA sample may be purified by either ethanol precipitation or dialysis. The following suggested protocols are for ligation reactions of 20ul. The volumes may be adjusted to suit the amount being prepared. Purifying DNA by Precipitation: Add 5 to 10 ug of tRNA to a 20ul ligation reaction. Adjust the solution to 2.5 M in ammonium acetate using a 7.5 M ammonium acetate stock solution. Mix well. Add two volumes of 100 % ethanol. Centrifuge at 12,000 x g for 15 min at 4C. Remove the supernatant with a micropipet. Wash the pellet with 60ul of 70% ethanol. Centrifuge at 12,000 x g for 15 min at room temperature. Remove the supernatant with a micropipet. Air dry the pellet. Resuspend the DNA in 0.5X TE buffer [5 mM Tris-HCl, 0.5 mM EDTA (pH 7.5)] to a concentration of 10 ng/ul of DNA. Use 1 ul per transformation of 20 ul of cell suspension. Purifying DNA by Microdialysis: Float a Millipore filter, type VS 0.025 um, on a pool of 0.5X TE buffer (or 10% glycerol) in a small plastic container. Place 20ul of the DNA solution as a drop on top of the filter. Incubate at room temperature for several hours. Withdraw the DNA drop from the filter and place it in a polypropylene microcentrifuge tube. Use 1ul of this DNA for each electrotransformation reaction.
Yes, several of our competent cells products are frozen with DMSO. The presence of DMSO (dimethylsulfoxide) will generally be indicated in the MSDS files if you have a question about a particular product, but here is a list of commonly used products that are known to have DMSO in the freezing buffer: One Shot OmniMAX 2 T1 Phage Resistant Cells, Cat. No. C8540-03 One Shot INV?F' Chemically Competent Cells, Cat. No. C2020-03 and C2020-06 One Shot MAX Efficiency DH5?-T1 Chemically Competent Cells, Cat. No. 12297-016 MAX Efficiency DH5?-T1 Phage Resistant Cells, Cat. No. 12034-013 MAX Efficiency DH5? Chemically Competent Cells, Cat. No. 18258-012 Library Efficiency DH5? Chemically Competent Cells, Cat. No. 18263-012 MAX Efficiency DH5? F'IQ Cells, Cat. No. 18288-019 MAX Efficiency Stbl2Chemically Competent Cells, Cat. No. 10268-019
Yes. Bacterial host cells will often degrade incoming DNA that has a methylation pattern that is "foreign" relative to that of the cell. Several host strains have been modified to accept mammalian methylation patterns. The modified markers include mcrA, mcrBC, and mrr. Also, endogenous (b-type) restriction endonucleases can be problematic. Modifications of the host to be rK- or rB- are necessary and include hsdR17(AK-, MK+), hsdR17(rK-, mK-), hsdS20(rB-, rB-) or hsdRMS. Strains with the hsdR17(rK-, mK+) mutation lack K-type restriction endonuclease, but contain K-type methylase. DNA prepared from hosts that are rK- mK- is unmethylated and will transform with lower efficiency in rK+ hosts. TOP10, DH10B, and OmniMAX2-T1 cells contain the mcr, mrr, and hsdRMS mutations. Mach1 and standard DH5? strains only have the hsdR17(rK- mK+) mutation and are not recommended for cloning eukaryotic genomic DNA.
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