One Shot™ TOP10 Electrocomp™ E. coli

One Shot™ TOP10 Electrocomp™ <i>E. coli</i>

Invitrogen™

One Shot™ TOP10 Electrocomp™ E. coli

Name: One Shot™ TOP10 Electrocomp™ E. coli
SKU: C404050
Price: 2716.00 CNY

Change view

Catalog Number	Quantity
C404050	11 x 50 μL, 10 Reactions
C404052	21 x 50 μL, 20 Reactions

2 Options

Catalog number C404050

Price (CNY)

2,716.00

Each

Add to cart

Quantity:

11 x 50 μL, 10 Reactions

Price (CNY)

2,716.00

Each

Add to cart

One Shot TOP10 Electrocomp E. coli cells are ideal for high-efficiency cloning and plasmid propagation. Provided at a transformation efficiency of >1 x 10¹⁰ cfu/ μg supercoiled DNA, these cells allow for stable replication of high copy number plasmids. TOP10 Electrocomp E. coli cells are transformed via electroporation and achieve higher transformation efficiencies than chemically competent cells. They can therefore be used in more challenging applications, including cloning low amounts of DNA or cDNA and gDNA library construction.

TOP10 E. coli cells are genetically similar to the DH10B strain but have been reported to be more resilient to stress conditions like osmotic shock and acidic pH stress. These cells carry mutations in the methylation-dependent restriction system (mcrA, mcrBC, and mrr) allowing them to clone both prokaryotic and eukaryotic genomic DNA, as well as efficient plasmid rescue from eukaryotic genomes. Similar to other DH strains, TOP10 has the lacZΔM15 genotype, providing for the option of blue-white screening on plates containing either X-Gal or Bluo-Gal.

One Shot TOP10 Electrocomp E. coli cells offer:

Transformation efficiencies of >1 x 10¹⁰ cfu/μg
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
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

TOP10 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^–mcrA Δ(mrr-hsdRMS-mcrBC) φ80lacZΔM15 ΔlacX74 recA1 araD139 Δ(ara-leu)7697 galU galK λ–rpsL(Str^R) endA1 nupG

Find the strain and format that fit your needs

We offer other DH strains in chemically competent and electrocompetent cell formats.

Electroporation cuvettes with 0.1 cm (Cat. No. P41050), 0.2 cm (Cat. No. P45050), and 0.4 cm (Cat. No. P46050) gaps are available.

The TOP10 strain is available in several MultiShot formats for high throughput applications.

Explore bacterial growth media formats.

Note: TOP10 cells do not require IPTG to induce expression from the lac promoter. A high-voltage electroporation apparatus is required.

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

Specifications

Antibiotic Resistance BacterialYes (Streptomycin)

Blue/White ScreeningYes (lacZΔM15)

Cloning Methylated DNAYes (mcrA)

Cloning Unstable DNANo

Contains F' EpisomeNo

High-throughput CompatibilityLow

Improves Plasmid QualityYes (endA1)

PlasmidMay be used for plasmids >20 kb

Preparing Unmethylated DNANo

Product LineOne Shot™

Product TypeElectrocompetent Cells

Quantity11 x 50 μL, 10 Reactions

Reduces RecombinationYes (recA13)

Shipping ConditionDry Ice

T1 Phage - Resistant (tonA)No

Transformation Efficiency LevelHigh Efficiency (>1 x 10¹⁰ cfu/μg)

FormatTube

SpeciesE. coli (K12)

Unit SizeEach

Contents & Storage

• One Shot TOP10 Electrocomp E. coli (11 x 50 μL)
Store at –80°C.

• pUC19 DNA (50 μL)
Store at –20°C.

• S.O.C. Medium (6 mL)
Store at room temperature.

Frequently asked questions (FAQs)

What is the difference between TOP10 and TOP10F' cells?

The only difference between TOP10 and TOP10F' cells is that the latter contain the F' episome that carries the tetracycline resistance gene and allows isolation of single-stranded DNA from vectors that have an f1 origin of replication. The F' episome also carries the lacIq repressor for inducible expression from trc, tac, and lac promoters using IPTG. TOP10F' cells require IPTG induction for blue/white screening.

I am trying to clone an insert that is supposedly pretty toxic. I used DH5? and TOP10 cells for the transformation and got no colonies on the plate. Do you have any suggestions for me?

If the insert is potentially toxic to the host cells, here are some suggestions that you can try:

- After transforming TOP10 or DH5? cells, incubate at 25-30°C instead of 37°C. This will slow down the growth and will increase the chances of cloning a potentially toxic insert.
- Try using TOP10F' cells for the transformation, but do not add IPTG to the plates. These cells carry the lacIq repressor that represses expression from the lac promoter and so allows cloning of toxic genes. Keep in mind that in the absence of IPTG, blue-white screening cannot be performed.
- Try using Stbl2 cells for the transformation.

Can I directly clone, propagate and express in BL21 without using TOP10?

It is imperative that a cloning strain such as TOP10 be used for characterization of the plasmid, propagation, and maintenance. BL21 cells are wild-type for endA and recA, which could result in poor miniprep quality and a greater chance of plasmid rearrangements due to recombination. In addition, BL21 cells contain the T7 RNA polymerase gene which is expressed at low levels even in the absence of inducer. If the gene is toxic to E. coli, plasmid instability and/or cell death can result.

I need to clone unmethylated DNA from a PCR reaction using a strain that has the hsdRMS mutation to avoid restriction after transformation. Is TOP10 suitable for my purposes?

Yes, TOP10 has the hsdRMS mutation, so this strain can be used to clone DNA from PCR reactions and other non-methylated sources. hsdRMS is a mutation in the system that E. coli uses to recognize foreign DNA. There are two parts to this system, methylation and restriction. E. coli methylate DNA at certain sequences, and if the DNA is not methylated at these sequences it will be recognized as foreign and restricted. Thus, if unmethylated DNA is transformed into E.coli that does not carry the hsdRMS genotype, it is recognized as foreign and enzymatically degraded.

Are TOP10 cells lacIq+ (plus) or lacIq- (minus)? That is, do they produce the lambda lacIq repressor protein?

TOP10 cells are lacIq- (minus). They do not have the lacIq gene and therefore do not produce the lacIq repressor protein. lacIq is most commonly found on an F' episome, and therefore is present in TOP10F', JM101, JM109, and NM522 strains.