DNA Polymerase I Large (Klenow) Fragment, Exonuclease Minus

DNA Polymerase I Large (Klenow) Fragment, Exonuclease Minus

DNA-Dependent DNA Polymerase that Lacks Both 5´→3´ and 3´→5´ Exonuclease Activities

  • May be heat-inactivated by incubating the enzyme at 75°C for 10 minutes
  • Provided with 10X Reaction Buffer: 500mM Tris-HCl (pH 7.2 at 25°C), 100mM MgSO4, 1mM DTT
  • Supplied at a concentration of 5–10u/μl

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Size: 100u
Catalog number: M2181

DNA Polymerase I Large (Klenow) Fragment, Exonuclease Minus, is a DNA-dependent DNA polymerase that lacks both the 5´→3´ and the 3´→5´ exonuclease activities present in intact E. coli DNA Polymerase I. Klenow Fragment, Exo Minus, is used for random primer labeling, DNA sequencing by the dideoxy method, and in strand displacement amplification (SDA). This enzyme will leave a single-base 3´ overhang on a significant proportion of DNA fragments during fill-in of 5´-overhangs. Therefore, Klenow Fragment, Exonuclease Minus, is not recommended for preparation of blunt-ended fragments for ligation.


  1. Derbyshire, V. et al. (1988) Science 240, 199–201.
  2. Sanger, F. et al. (1977) Proc. Natl. Acad. Sci. USA 74, 5463–7.
  3. Feinberg, A.P. and Vogelstein, B. (1984) Anal. Biochem. 137, 266–7.
  4. Walker, G.T. (1993) PCR Meth. Appl. 3, 1–6.
  5. Clark, J.M. et al. (1987) J. Mol. Biol. 198, 123–7.

Storage Buffer: 50mM Tris-HCl (pH 7.5 at 25°C), 1mM DTT, 0.1mM EDTA and 50% (v/v) glycerol.

Source: Recombinant E. coli strain.

QC Tests: Activity, SDS-PAGE/purity, endonuclease, DNase, RNase.

Unit Definition: One unit is defined as the amount of enzyme that incorporates 10nmol of total deoxyribonucleotides into TCA-insoluble material in 30 minutes at 37°C. The reaction conditions are: 67mM potassium phosphate (pH 7.4 at 25°C), 6.7mM MgCl2, 1mM DTT, 50μg/ml activated calf thymus DNA, and 33μM dATP, dCTP, dGTP and dTTP (a mix of unlabeled and [3H]dTTP).


Complete Protocol

DNA Polymerase I Large (Klenow) Fragment, Exonuclease Minus Protocol


What’s in the box?
Size: 100u

Item Part # Size
DNA Polymerase 10X Buffer M195A 1 × 1ml
Klenow Fragment, Exonuclease Minus M218A 1 × 100u

Use Restrictions

For Laboratory Use. Outside of the United States, this product is intended for research use only unless otherwise stated.

Storage Conditions