pENTR™/D-TOPO™ Cloning Kit, with One Shot™ TOP10 Chemically Competent E. coli
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Invitrogen™

pENTR™/D-TOPO™ Cloning Kit, with One Shot™ TOP10 Chemically Competent E. coli

The pENTR™/D-TOPO™ Cloning Kits utilize a highly efficient, 5-minute cloning strategy (“TOPO™ Cloning”) to directionally clone a blunt-end PCR productRead more
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Catalog number K240020
Price (USD)
648.00
Each
Add to cart
Price (USD)
648.00
Each
Add to cart
The pENTR™/D-TOPO™ Cloning Kits utilize a highly efficient, 5-minute cloning strategy (“TOPO™ Cloning”) to directionally clone a blunt-end PCR product into a vector for entry into the Gateway™ System or the MultiSite Gateway™ System. Blunt-end PCR products clone directionally at greater than 90% efficiency, with no ligase, post-PCR procedures, or restriction enzymes required.

The kit comes with everything necessary to clone and select your PCR amplified gene of interest:

Gateway™ System Ready—Rapidly shuttle cloned genes between multiple vector systems
Fast and Easy—Go from PCR to Gateway™ Entry clone in just 3 steps and as little as ∼5 minutes hands on time
Efficient—Achieve over 90% clones with correct insert in the right direction
Proven—Reliable performance for over a decade

pENTR™ /D-TOPO™ Cloning Kits Overview

VECTOR

pENTR™ /D-TOPO™ Vector Directional cloning vector for entry to the Gateway System

CLONING METHOD

Directional TOPO™ Cloning Topoisomerase I based ∼5 minute directional ligation of blunt-end proofreading polymerase-amplified PCR products to the vector

COMPETENT CELLS

Two Options Choose from kits with either high efficiency, or fast growing competent cells
Simple Access to the Gateway™ System
For access to the Gateway™ System, just PCR amplify your gene of interest and add the product straight to the provided topoisomerase charged pENTR™/D-TOPO™ vector, incubate 5 minutes, and transform the provided competent E. coli cells. The resulting attL containing Gateway™ Entry clones are ready for efficient recombination with your choice of Gateway™ Destination vectors.

Optimized pENTR™/D-TOPO™ Vector
The pENTR™/D-TOPO™ vector (Figure 1) includes M13 and T7 primer sequencing sites and attL recombination sites flanking the PCR product insertion site. This allows clones to be easily sequence verified and recombined into your choice of attR containing Gateway™ destination vectors. A Kanamycin resistance gene and a pUC origin are used for selection and high-copy propagation in E. coli.

Simplified Directional Cloning
With Directional TOPO™ cloning technology there is no need for PCR clean up, vector preparation, or other time-intensive DNA manipulation steps. Just add your PCR reaction straight to the provided topoisomerase charged vector, incubate 5 minutes, transform, and obtain up to 90% directionally inserted clones. A four base overhang on the vector pairs with a four base sequence designed into the forward primer used in your PCR reaction to provide directionality to the topoisomerase ligation reaction (Figure 2).

The Power of Gateway™ Recombination Cloning Technology
Gateway™ recombination cloning technology circumvents the limitations of restriction mediated cloning, enabling you to access virtually any expression system in a simple one hour, 99%-efficient and reversible, Gateway™ recombination reaction. The ability to move the same sequence of DNA between different vectors without using restriction enzymes, ligase, subcloning steps, screening of countless colonies, or re-sequencing will help save you time, money, and effort.

Leading Cloning Technologies
When it comes to cloning, TOPO™ cloning technology and Gateway™ recombination cloning technology have been a reliable partner for thousands of scientists for over ten years. Fast, simple to use, and efficient, TOPO™ cloning and Gateway™ recombination allow for rapid cloning and subsequent transferring of genes between a wide assortment of Gateway™ expression vectors.

Kit Options
The pENTR™/D-TOPO™ Cloning Kit can be purchased with either TOP10 competent cells for standard cloning or Mach1™-T1R competent cells for fast growth.

For Research Use Only. Not intended for use in animal or human therapeutic or diagnostic use.
For Research Use Only. Not for use in diagnostic procedures.
Specifications
Cloning MethodDirectional TOPO™
No. of Reactions20 reactions
Product LineOne Shot™
Product TypeTOPO Cloning Kit
VectorpENTR
Unit SizeEach
Contents & Storage
pENTR™⁄D-TOPO™ Cloning Kit contains pENTR⁄D-TOPO™ vector, dNTPs, salt solution, sterile water, universal M13 sequencing primers, OneShot™ TOP10 Chemically E. coli, S.O.C. Medium, and a pUC19 control plasmid. Store Competent E. coli at -80°C. Store all other components at -20°C.

Frequently asked questions (FAQs)

Your Gateway-adapted TOPO vectors are supplied with a control template and control primers. Can I obtain the sequence of the control template?

The sequence of the control template is proprietary.

I am using a Directional TOPO Cloning vector for cloning my PCR product. I have screened a bunch of colonies but they all contain my insert cloned in the reverse direction. How can I solve this problem?

Here are possible causes and suggestions:

- Incorrect PCR primer design: Make sure that the forward PCR primer contains the sequence, CACC, at the 5' end. The 4 nucleotides, CACC, base pair with the overhang sequence, GTGG, in the Directional TOPO vector.
- Reverse PCR primer is complementary to the GTGG overhang at the 5' end: Make sure that the reverse PCR primer does not contain the sequence, CACC, at the 5' end.
- Use a thermostable, proofreading polymerase such as Accuprime Pfx DNA Polymerase (Cat. No. 12344024) to produce blunt-end PCR products.

How large of a PCR product can I recombine with a pDONR vector via BP cloning? Does the same apply for TOPO-adapted Entry vectors?

There is no theoretical limit to insert size for a BP reaction with a pDONR vector. Maximum size tested in-house is 12 kb. TOPO vectors are more sensitive to insert size and 3-5 kb is the upper limit for decent cloning efficiency.

How should I clean up my attB-PCR product?

After generating your attB-PCR product, we recommend purifying it to remove PCR buffer, unincorporated dNTPs, attB primers, and any attB primer-dimers. Primers and primer-dimers can recombine efficiently with the Donor vector in the BP reaction and may increase background after transformation into E. coli, whereas leftover PCR buffer may inhibit the BP reaction. Standard PCR product purification protocols using phenol/chloroform extraction followed by ammonium acetate and ethanol or isopropanol precipitation are not recommended for purification of the attB-PCR product as these protocols generally have exclusion limits of less than 100 bp and do not efficiently remove large primer-dimer products. We recommend a PEG purification protocol (see page 17 of the Gateway Technology with Clonase II manual). If you use the above protocol and your attB-PCR product is still not suitably purified, you may further gel-purify the product. We recommend using the PureLink Quick Gel Extraction kit.

I'm getting low cloning efficiency with my directional TOPO cloning reaction. What should I do?

Here are suggestions to try to increase your cloning efficiency with dTOPO cloning:

- Ensure that the 5' primer has CACC and the 3' primer does not have sequence similarity to GTGG.
- The molar ratio of PCR product: TOPO vector used is critical to success.

We recommend using a 1:1 to 2:1 molar ratio, starting with a 1:1 of PCR product: TOPO vector. The TOPO cloning efficiency decreases significantly if the ratio of PCR product: TOPO vector is <0.1:1 or >5:1. These results are generally obtained if too little PCR product is used (i.e., PCR product is too dilute) or if too much PCR product is used in the TOPO cloning reaction. If the yield of the PCR product has been quantitated, the concentration of the PCR product may need to be adjusted before proceeding to TOPO cloning. For pENTR TOPO vectors, using 1-5 ng of a 1 kb PCR product or 5-10 ng of a 2 kb PCR product in a TOPO cloning reaction generally results in a suitable number of colonies.