Description
Digest duplex DNA in a 3´ to 5´ direction from a nick, blunt end, or 3´-recessed end, producing stretches of ssDNA.
Key features
- Produce stretches of ssDNA in dsDNA templates containing nicks, blunt ends or recessed 3' ends
- Protect protruding 3' ends because this exonuclease will not start digestion at protruding 3' overhangs
Product information
Exonuclease III digests duplex DNA in a 3´ to ;5´ direction from a nick, a blunt end, or 3´-recessed end, producing stretches of ssDNA on the opposite strand. 5,6 Under defined reaction conditions, DNA degradation by Exonuclease III proceeds at a uniform rate yielding predictable and reproducible digestion results.
Applications
- Production of intermediates for site-directed mutagenesis. 1-3
- Production of strand-specific radiolabelled probes. 4
Because the rate of exonucleolytic excision of deoxyribonucleotides by Exonuclease III is dependent upon reaction factors including temperature, ionic strength, template sequence, and enzyme-to-DNA ratios, 4,7 each template must be optimised using sample digestions to achieve the desired excision rate.
Exonuclease III is not active on 3´-protruding ends of four bases or more in length, ssDNA, or on thioester-linked nucleotides. 2 The enzyme also has intrinsic RNase H, 3´-DNA phosphatase, and apurinic DNA endonuclease activities. 1,6
Product specifications and usage
Unit Definition: One unit of Exonuclease III catalyses the release of 1 nmol of acid-soluble nucleotides from double stranded calf thymus DNA in 30 minutes at 37 °C under standard assay conditions.
Storage Buffer: 50% glycerol containing 50 mM Tris-HCl (pH 7.5), 0.1 M NaCl, 0.1 mM EDTA, 1 mM DTT, and 0.1% Triton® X-100.
Exonuclease III 10X Reaction Buffer: 330 mM Tris-acetate (pH 7.5), 660 mM potassium acetate, 100 mM magnesium acetate, and 5 mM DTT.
Quality Control: Exonuclease III is free of detectable exogenous RNase, endonuclease, and single-stranded exonuclease activities.
SDS
MANUAL
PIS