TOP10F' Electrocomp™ Kit
TOP10F' Electrocomp™ Kit
Invitrogen™

TOP10F' Electrocomp™ Kit

TOP10F´ Electrocomp Kit E. coli cells are identical to TOP10 cells, with the addition of an F´ episome. The F´Read more
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Catalog number C66511
Price (USD)
552.00
Each
Add to cart
Price (USD)
552.00
Each
Add to cart

TOP10F´ Electrocomp Kit E. coli cells are identical to TOP10 cells, with the addition of an F´ episome. The F´ episome carries the tetracycline resistance gene and allows isolation of single-stranded DNA (ssDNA) from vectors that have an f1 origin of replication. In addition, the F´ episome carries the lacIq repressor for inducible expression from trc, tac, and lac promoters using IPTG.

TOP10F´ competent cells are transformed via electroporation, thus achieving higher transformation efficiencies than chemically competent cells and may be used in more challenging applications, including cloning a low amount of DNA or cDNA and gDNA library construction. These cells allow stable replication of high copy number plasmids and are provided at a transformation efficiency of >1 x 1010 cfu/ μg supercoiled DNA and are ideal for high-efficiency cloning and plasmid propagation.

As a derivative of TOP10, TOP10F´ cells carry mutations in the methylation-dependent restriction system (mcrA, mcrBC, and mrr) allowing one to clone both prokaryotic and eukaryotic genomic DNA, as well as efficient plasmid rescue from eukaryotic genomes. Similar to other DH strains, the TOP10 strain also has recA1 and endA1 mutations to increase insert stability and improve the quality of plasmid DNA prepared from minipreps.

TOP10F´ Electrocomp Kit E. coli cells offer:
• Transformation efficiencies of >1 x 1010 cfu/μg
• Stable F´ episome that allows isolation of ssDNA and carries lacIq repressor for inducible expression from trc, tac, and lac promoters 
• hsdR for efficient transformation of unmethylated DNA from PCR amplifications
• mcrA for efficient transformation of methylated DNA from genomic preparations
• lacZΔM15 for blue/white color screening of recombinant clones on plates containing either X-Gal or Bluo-Gal
• 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

Note: TOP10F´ cells require IPTG induction for blue-white color screening. A high-voltage electroporation apparatus is also required.

Genotype
F´ [lacIq, Tn10(TetR)] mcrA Δ(mrr-hsdRMS-mcrBC) φ80lacZΔM15 ΔlacX74 recA1 araD139 Δ(ara-leu)7697 galU galK rpsL(StrR) endA1 nupG

Find the strains and formats that fit your needs
We offer other DH strains in chemically competent and electrocompetent cell.
Electroporation cuvettes with 0.1 cm, 0.2 cm, and 0.4 cm gaps are available.
The TOP10 strain is available in several MultiShot formats for high throughput applications.
We offer other strains for ssDNA production, such as DH12S.
Explore bacterial growth media formats.

For Research Use Only. Not for use in diagnostic procedures.
Specifications
Product TypeElectrocompetent Cells
Improves Plasmid QualityYes (endA1)
Cloning Methylated DNAYes (mcrA)
Transformation Efficiency LevelHigh Efficiency (>1010 cfu/μg)
Cloning Unstable DNANot suitable for cloning unstable DNA
Blue/White ScreeningYes (lacZΔM15)
PlasmidMay be used for plasmids >20 kb
Preparing Unmethylated DNANo
Reduces RecombinationYes (recA1)
Shipping ConditionDry Ice
SpeciesE. coli (K12)
FormatTube
Product LineElectrocomp™
Quantity10 x 100 μL
Unit SizeEach
Contents & Storage
• TOP10F' Electrocomp E. coli (10 x 100 μL)
Store at -80°C.

• pUC19 vector (50 μL at 10 pg/μL)
Store pUC19 DNA at -20°C.

• S.O.C. Medium (15 mL)
Store at room temperature.

Frequently asked questions (FAQs)

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.

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.

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.

Find additional tips, troubleshooting help, and resources within our PCR and cDNA Synthesis Support Center.