Zero Blunt™ TOPO™ PCR Cloning Kit provides a highly efficient, 5-minute, one-step cloning strategy ("TOPO™ Cloning") for the direct insertion of blunt-ended PCR products amplified with proofreading thermostable polymerases into a plasmid vector. Each kit has the Zero Blunt™ TOPO™ vector (see figure) containing the ccdB gene for positive selection, only permitting growth of plasmid vectors with recombinants. Zero™ Blunt™ TOPO™ kits are available with a variety of competent cells, or without competent cells, depending on your needs and budget. Features of the Zero™ Blunt™ TOPO™ PCR Cloning Kits:

Fast and easy—go from PCR to clones in just 3 steps and in as little as 5 minutes hands-on time
Efficient—obtain up to 95% clones with correct insert
Proven—reliable performance for over a decade with over 4,000 citations
Simple —no ligase, post-PCR procedures, or PCR primers containing specific sequences are required.

Zero Blunt™ TOPO™ Cloning Kits—overview

Vector: pCR™Blunt II-TOPO™ vector—contains the ccdB gene, allowing for direct selection of recombinants

Cloning method: TOPO™ cloning—Topoisomerase I–based, 5-minute ligation of blunt-ended PCR products amplified with proofreading thermostable polymerases

Competent cells: Various options—choose from kits with either general, high-efficiency, bacteriophage T1-resistant, fast-growing competent cells, or use your own.

pCR™Blunt II-TOPO™ vector—designed for proofreading polymerases
The pCR™Blunt II-TOPO™ vector is designed to clone blunt-ended PCR products generated by thermostable proofreading polymerases such as Platinum™ Pfx DNA Polymerase. The pCR™Blunt II-TOPO™ vector contains:

• EcoRI sites flanking the PCR product insertion site for easy excision of inserts
• Kanamycin and Zeocin™ resistance genes for your choice of selection in E. coli
• SP6 promoter/primer site for in vitro RNA transcription and sequencing
• M13 forward and reverse primer sites for sequencing or PCR screening

pCR™Blunt II-TOPO™ clone selection
pCR™-Blunt II-TOPO™ allows for direct selection of recombinants via disruption of the lethal E. coli gene, ccdB. The vector contains the ccdB gene fused to the C-terminus of the LacZα fragment. Ligation of a blunt-end PCR product disrupts expression of the LacZα-ccdB gene fusion, permitting growth of only positive recombinants upon transformation. Cells that contain non-recombinant vector are killed upon plating. Therefore, blue/white screening is not required.

Simplified TOPO™-based cloning
Using TOPO™ cloning technology, there is no need for PCR primers containing specific sequences, post-PCR procedures, vector preparation, or other time-intensive DNA manipulation steps. Just add your PCR reaction straight to the provided topoisomerase-charged vector, incubate 5 minutes, and transform E. coli competent cells.

Efficient cloning
With up to 95% of clones carrying the desired insert, you can screen less clones, saving you time and money. The pCR™Blunt II-TOPO™ vector used in this kit comes with lethal ccdB gene for efficient selection of blunt-ended PCR recombinants products generated bythermostable proofreading polymerases.

The standard in cloning
When it comes to cloning, TOPO™ cloning technology has been a reliable partner for thousands of scientists for over ten years. Fast, simple-to-use, and efficient, TOPO™ cloning has been applied to many different vectors for a wide array of applications.

Zero Blunt™ TOPO™ PCR Cloning™ Kit options
The Zero Blunt™ TOPO™ PCR Cloning Kit for direct insertion of blunt-ended PCR products into a plasmid vector can be purchased with a variety of competent cells that deliver different advantages depending upon your needs:

General cloning: TOP10 cells (Cat. No. K2800-20, K2800-40)
High-efficiency cloning: TOP10 Electrocomp™ Cells (Cat. No. K2860-01, K2860-40)
General cloning, bacteriophage T1 resistance: DH5α-T1R (Cat. No. K2820-20, K2820-40)
Fast growth: Mach1™-T1R Chemically Competent E. Coli (Cat. No. K2830-20)
Provide your own: for flexibility and to save money (Cat. No. 450254)

We also offer a version of the kit that includes a PureLink™ Quick Plasmid Miniprep Kit (Cat. No. K2800-02) for use in isolation of clean, sequencing-ready, recombinant plasmid.