Thermo Scientific Klenow fragment (exo-) is a large fragment of DNA polymerase I. It exhibits 5'→3' polymerase activity but lacks the 3'→5' and 5'→3' exonuclease activities of DNA polymerase I. The 3'→5' exonuclease activity of the enzyme is eliminated by mutations in the 3'→5'-exonuclease active site.

Product Advantages

• Lack of 3'→5' exonuclease activity
• Incorporation of modified nucleotides (e.g., Cy3, Cy5, fluorescein, rhodamine, aminoallyl, biotinylated nucleotides)
• Active in restriction enzymes, PCR and RT buffers

Applications
• Random-primed DNA labeling
• Labeling by filling in the 5'-overhangs of dsDNA
• Strand displacement amplification (SDA)
• DNA sequencing by the Sanger method

Remarks

Klenow fragments (exo-) are not recommended for use in DNA blunt-ending reactions prior to DNA ligation because they often add one or more fragments to the 3'-end of the blunt-ended DNA substrate in a non-template-directed manner. multiple additional nucleotides.