Klenow Fragment, Exonuclease Free (Exo-)

Catalog No. 1092

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Price From: $52.00

Quick Overview

Large fragment of E. coli DNA Polymerase I enzyme which lacks boths the 3'→5' exonuclease and the 5'→3' exonuclease activities of Polymerase l

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Price From: $52.00



Escherichia coli


  • Lacks both 3'→5' exonuclease and 5'→3' exonuclease activities (1)
  • Ultrapure recombinant enzyme


  • Used for Sanger dideoxy sequencing (2)
  • Suitable for second strand cDNA synthesis (3)
  • Used for 3'-end labeling and filling in 5'-protruding sticky ends (4)

Reagents Supplied

10X Klenow Fragment (Exo-) Reaction Buffer

Unit Definition

One unit is the amount of enzyme required to incorporate 10 nmoles of total nucleotide into acid insoluble form at 37°C for 30 minutes

Heat Inactivation

75ºC for 15 minutes


5 - 10 units/µl

Storage Buffer

50 mM potassium phosphate (pH 7.0)
0.25 mM dithiothreitol
50% glycerol

Assay Conditions

67 mM potassium phosphate (pH 7.4)
6.7 mM MgCl2
1 mM dithiothreitol
0.033 mM of each dCTP, dGTP, dTTP and [α-32P]dATP
4.5 µg activated DNA
Incubation is for 30 minutes at 37°C in a total reaction volume of 
100 µl

Quality Control

All preparations are assayed for contaminating 3'- and 5'-exonuclease and endonuclease activities

Storage Conditions

Store at -20°C
Product shipped on dry ice


Certificate of Analysis PDF -Current Lot


1. Derbyshire, V., Freemont, P.S., Sanderson, M.R., Beese, L., Friedman, J.M., Joyce, C.M. and Steitz, T.A. (1988) Science 240, 199-201
2. Sanger, F., Nicklen, S. and Coulson, A.R. (1977) Proc. Natl. Acad. Sci. USA 74, 5463-5467
3. Houdebine, L.M. (1976) Nucleic Acids Res. 3, 615-630
4. Sambrook, J., Fritsch, E.F., and Maniatis, T. (1989) Mol. Cloning: A Laboratory Manual, Second Ed. pp. 5.34, 5,4-5.41