Invitrogen™ One Shot™ OmniMAX™ 2 T1^R Chemically Competent E. coli

Catalog No.	Quantity
C854003	21 x 50 μL/tube

Catalog No. C854003 Supplier Invitrogen™ Supplier No. C854003

Description

Includes

One Shot OmniMAX 2 T1R E. coli: 21 vials, 50μL each, pUC19 DNA (10pg/μL): 1 vial, 50μL, S.O.C. medium: 1 bottle, 6mL

The One Shot OmniMAX 2 T1^R 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.

The One Shot OmniMAX 2 T1^R 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 T1^R is a versatile strain, perfect to use in all cloning applications, including Gateway technology and TOPO PCR cloning.

OmniMAX 2 T1^R 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 T1^R 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 T1^R 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 T1^R 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 T1^R 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 T1^R and other strains are available in MultiShot formats for high throughput applications.

Order Info

Shipping Condition: Dry Ice

Specifications

• Product Type: Chemically Competent Cells
• Contains F' Episome: Yes
• Improves Plasmid Quality: Yes (endA1)
• Cloning Methylated DNA: Yes (mcrA)
• Transformation Efficiency Level: High Efficiency (>1 x 10⁹ cfu/μg)
• Content And Storage: • One Shot OmniMAX 2 T1^R E. coli (21 x 50 μL)
  Store Competent Cells at –80°C.
  
  • pUC19 DNA (50 μL at 10 pg/μL)
  Store pUC19 DNA at –20°C.
  
  • S.O.C. Medium (6 mL)
  Store S.O.C. Medium at 4°C or room temperature.
  
  
• Antibiotic Resistance Bacterial: Yes (Tetracycline)
• Cloning Unstable DNA: Not suitable for cloning unstable DNA
• Blue/White Screening: Yes (lacZΔM15)
• High-throughput Compatibility: Low
• Plasmid: May be used for plasmids >20 kb
• Preparing Unmethylated DNA: No
• Reduces Recombination: Yes (recA1)
• Shipping Condition: Dry Ice
• T1 Phage - Resistant (tonA): Yes
• Species: E. coli (K12)
• Format: Tube
• Product Line: One Shot
• Quantity: 21 x 50 μL/tube

Frequently Asked Questions (FAQs)

What strain should I use to transform my library?

OmniMAX 2 is the preferred strain for transforming libraries because of its high transformation efficiency and genomic cloning compatibility characteristics.

What advantages do your Stbl2 cells offer over other cloning strains?

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. 

How do you recommend that I prepare my DNA for successful electroporation of E. coli?

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.

Do any Invitrogen competent cells contain DMSO in the freezing medium?

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

Does the methylation status of DNA affect its ability to be cloned?

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.

Can encapsulated phagemid DNA or M13 phage be used to infect bacteria?

Single-stranded DNA viral particles like M13 require the presence of an F pilus in order to infect E. coli. This criterion is met by TOP10F', DH5? F'IQ, INV?F', Stbl4, OmniMAX2-T1 and DH12S cells. These cells are not traD mutants, which effectively allows the cells to retain the F' episome. Transforming single-stranded DNA can cause a 100- to 1,000-fold reduction in efficiency compared to viral particles.

Is S.O.C. medium absolutely required when recovering competent bacterial cells during transformation?

Many media can be used to grow transformed cells, including standard LB, SOB or TB broths. However, S.O.C. is the optimal choice for recovery of the cells before plating. The nutrient-rich formula with added glucose is often important for obtaining maximum transformation efficiencies.

Why is it necessary to dilute ligated DNA products before adding them to competent bacterial cells?

Components of the ligation reaction (enzymes, salts) can interfere with transformation, and may reduce the number of recombinant colonies or plaques. We recommend a five-fold dilution of the ligation mix, and adding not more than 1/10 of the diluted volume to the cells. For best results, the volume added should also not exceed 10% of the volume of the competent cells that you are using.

When should DMSO, formamide, glycerol and other cosolvents be used in PCR?

Cosolvents may be used when there is a failure of amplification, either because the template contains stable hairpin-loops or the region of amplification is GC-rich. Keep in mind that all of these cosolvents have the effect of lowering enzyme activity, which will decrease amplification yield. For more information see P Landre et al (1995). The use of co-solvents to enhance amplification by the polymerase chain reaction. In: PCR Strategies, edited by MA Innis, DH Gelfand, JJ Sninsky. Academic Press, San Diego, CA, pp. 3-16.

Additionally, when amplifying very long PCR fragments (greater than 5 kb) the use of cosolvents is often recommended to help compensate for the increased melting temperature of these fragments.

How can AmpliTaq DNA Polymerase be inactivated after PCR?

There are several approaches that can be taken to inactivate the AmpliTaq DNA Polymerase after PCR.

(1) Because AmpliTaq DNA Polymerase is thermostable, it is necessary to heat it to high temperatures in order for it to be inactivated. Typically, a 99-100 degrees C for 10 min is sufficient.

(2) Raising the EDTA concentration to 10 mM will chelate any free Mg2+. Mg2+ is necessary for enzyme activity. By removing the Mg2+ the enzyme will no longer exhibit enzyme activity.

(3) Phenol-chloroform extraction of the PCR product and ethanol precipitation will also inactivate AmpliTaq DNA Polymerase.

For Research Use Only. Not for use in diagnostic procedures.