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Invitrogen™ One Shot™ INVαF' Chemically Competent E. coli
Description
One Shot INVαF´ Chemically Competent E. coli are designed to stably replicate high-copy number plasmids. They allow for the preparation of high quality plasmid DNA with less carry over contaminants as compared to other popular strains such as JM109 and can achieve a transformation efficiency of >1 x 108 cfu/μg supercoiled plasmid.
INVαF´ cells carry the F´ episome and so can be utilized to produce single-stranded DNA (ssDNA) from vectors that have an f1 origin of replication. This strain is related to DH strains and features similar genetic traits and benefits. The lacZΔM15 marker provides α-complementation of the ß-galactosidase gene from pUC or similar vectors and can be used for blue-white screening of colonies on bacterial plates containing Bluo-Gal or X-Gal. In addition to supporting blue/white screening, recA1 and endA1 mutations increase insert stability and improve the quality of plasmid DNA.
One Shot INVαF´ Chemically Competent E. coli cells offer:
• Transformation efficiencies of >1 x 108 cfu/μg
• Stability and exceptional quality of high-copy number plasmid DNAb
• Blue-white screening of recombinant clones (lacZΔM15)
• Reduction of homologous recombination of transformed plasmids (recA1)
• Increased quality of plasmid DNA preparations (endA1)
• Production and rescue of ssDNA from vectors carrying the f1 origin of replication (F´)
Note: INVαF´ cells do not require IPTG to induce expression from the lac promoter.
Convenient and efficient format
One Shot INVαF´ Chemically Competent E. coli cells are supplied in the convenient, single-reaction One Shot format. Each tube contains enough cells for one complete transformation, reducing freeze-thaw cycles and limiting money wasted on unused cells.
Genotype
F´ endA1 recA1 hsdR17 (rK–, mK+) supE44 thi-1 gyrA96 relA1 φ80lacZΔM15 Δ(lacZYA-argF)U169 λ–
Genetic marker descriptions
Find the strain and format that fit your needs
• A variety of DH strains are available in chemically competent and electrocompetent cell formats.
• We offer other strains for ssDNA production, such as TOP10F´ (Cat. No. C303003) or electrocompetent DH12S (Cat. No. 18312017).
• MultiShot formats are available for high throughput applications.
Specifications
Specifications
| Product Type | Chemically Competent Cells |
| Contains F' Episome | Yes |
| Improves Plasmid Quality | Yes (endA1) |
| Cloning Methylated DNA | Yes (hsd) |
| Transformation Efficiency Level | Medium Efficiency (1 x 108 to 1 x 109 cfu/μg) |
| Content And Storage | • One Shot INVαF' Chemically Competent E. coli (21 x 50 μL) Store Competent Cells at –80°C. • pUC19 plasmid (50 μL at 10 pg/μL) Store pUC19 plasmid at –20°C. • S.O.C. Medium (6 mL) Store S.O.C. Medium at 4°C or room temperature. |
| Antibiotic Resistance Bacterial | No |
| Cloning Unstable DNA | Not suitable for cloning unstable DNA |
| Blue/White Screening | Yes (lacZΔM15) |
| High-throughput Compatibility | Low |
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Frequently Asked Questions (FAQs)
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
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.
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.
For Research Use Only. Not for use in diagnostic procedures.