Thermo Scientific™ Klenow Fragment (10 U/μL)

Thermo Scientific™ Klenow Fragment is the large fragment of E. coli DNA Polymerase I. It retains 5′→3′ polymerase activity and 3′→5′ exonuclease (proofreading) activity, but lacks the 5′→3′ exonuclease function of DNA polymerase I. This enzymatic profile makes it especially useful for applications requiring DNA synthesis without degradation of template DNA.

Klenow Fragment is widely used for DNA blunting, labeling, sequencing, mutagenesis, and cDNA second-strand synthesis. It is compatible with commonly used reaction buffers, including restriction enzyme buffers, PCR buffers, RT buffers, and T4 DNA Ligase buffers, providing maximum flexibility in molecular biology workflows.

Key Features

• Versatile activity – 5′→3′ polymerase and 3′→5′ proofreading exonuclease activity.
• Modified nucleotide incorporation – efficiently incorporates Cy3, Cy5, aminoallyl, biotin, digoxigenin, and fluorescently labeled nucleotides.
• Buffer compatibility – fully active in restriction enzyme, PCR, RT, and ligation buffers.
• Reliable performance – high-quality enzyme for consistent and reproducible results across a range of DNA manipulations.

Applications

• DNA blunting – fill-in of 5′ overhangs.
• Random-primed DNA labeling – using modified or labeled nucleotides.
• Fill-in reactions – labeling 5′ overhangs of dsDNA.
• DNA sequencing – Sanger dideoxy sequencing method.
• Site-directed mutagenesis – with synthetic oligonucleotides.
• Second strand synthesis – in cDNA cloning workflows.

Technical Specifications

Available Formats

Thermo Scientific™ Klenow Fragment (10 U/µL) is a robust and versatile DNA polymerase fragment ideal for DNA labeling, blunting, sequencing, and mutagenesis. With proofreading capability, broad buffer compatibility, and reliable incorporation of modified nucleotides, it is a trusted enzyme for molecular cloning and genetic engineering workflows requiring precision and reproducibility.