Product Class: Other

Thermolabile Exonuclease I
Gray property icon for NEB r3.1 recombinant Gray property icon for incubation temperature 37° Gray property icon for heat inactivation 80°

Interested in a 5-minute protocol? Try out the Exo-CIP™ Rapid PCR Cleanup Kit (NEB #E1050)

We are excited to announce that all reaction buffers are now BSA-free. NEB began switching our BSA-containing reaction buffers in April 2021 to buffers containing Recombinant Albumin (rAlbumin) for restriction enzymes and some DNA modifying enzymes. Find more details at www.neb.com/BSA-free.

Product Introduction

Exonuclease I (E.coli), Thermostable Exonuclease I, Exonuclease T mechanism


  • DNA specific exonuclease
  • Catalyzes the removal of nucleotides from linear single-stranded DNA in the 3' to 5' direction
  • Unlike Exonuclease I (NEB #M0293), Thermolabile Exonuclease I can be quickly heat inactivated at 80°C in 1 minute
  • Need help finding the right exonuclease for your experiments? Try Exo Selector 

Thermolabile Exonuclease I is ideal for:

  • Removal of single-stranded primers in PCR reactions prior to DNA sequencing or SNP analysis
  • Removal of single-stranded primers for nested PCR reactions
  • Removal of linear single-stranded DNA, leaving behind double-stranded DNA in the sample
Bioz Badge Exists : True
Catalog # Size Concentration
M0568S 3000 units 20000 units/ml
M0568L 15000 units 20000 units/ml

Product Information

Description

Thermolabile Exonuclease I catalyzes the removal of nucleotides from single-stranded DNA (ssDNA) in the 3′ to 5′ direction.

 

Figure 1: Heat inactivation profile of Thermolabile ExoI

Gel comparing NEBuffer 3.1 and Taq DNAP-Buffer for Thermolabile Exonuclease I

Thermolabile ExoI can be heat inactivated quickly to speed up downstream applications. This data demonstrates that Thermolabile ExoI can be heat inactivated at 80°C for 1 min, 65°C for 4 min or 60°C for 15 min in both NEBuffer 3.1 as well as Standard Taq Reaction Buffer.

Product Source

An E. coli strain that carries a cloned Thermolabile Exonuclease I gene originating from a psychrophilic marine bacterium.
This product is related to the following categories:
Exonucleases and Non-specific Endonucleases,

Reagents Supplied

Reagents Supplied

The following reagents are supplied with this product:

NEB # Component Name Component # Stored at (°C) Amount Concentration

Properties & Usage

Unit Definition

One unit of Thermolabile Exonuclease I is defined as the amount of enzyme that will catalyze the release of 2 nmol of acid-soluble nucleotide in a total reaction volume of 100 μl in 6 minutes at 37°C in 50 mM Tris-HCl (pH 7.9), 100 mM NaCl, 10 mM MgCl2 and 100 μg/ml BSA with 0.17 mg/ml single-stranded [3H]-E. coli DNA.

Reaction Conditions

1X NEBuffer™ r3.1
Incubate at 37°C

1X NEBuffer™ r3.1
100 mM NaCl
50 mM Tris-HCl
10 mM MgCl2
100 µg/ml Recombinant Albumin
(pH 7.9 @ 25°C)

Storage Buffer

10 mM Tris-HCl
0.1 mM EDTA
1 mM DTT
0.25 M NaCl
50% Glycerol
200 µg/ml BSA
pH 7.4 @ 25°C

Heat Inactivation

80°C for 1 minute

Unit Assay Conditions

50 mM Tris-HCl (pH 7.9), 10 mM MgCl2, 100 mM NaCl, 100 μg/ml BSA and 0.17 mg/ml single-stranded [3H]-E.coli DNA.

Application Features

  • Removal of single-stranded primers in PCR reactions prior to DNA sequencing or SNP analysis
  • Removal of single-stranded primers for nested PCR reactions
  • Removal of single-stranded DNA from dsDNA

Product Notes

  1. This enzyme can be heat inactivated at 80°C for 1 minute, 65°C for 5 minutes or 60°C for 15 minutes.
  2. Thermolabile ExoI is active in the presence of 25 mM to 200 mM NaCl.
  3. If the amount of ssDNA to be degraded needs to be increased, we recommend adding more enzyme instead of extending the reaction time.
  4. Phosphorothioate (PT) bond is resistant to Thermolabile Exonuclease I cleavage. However, only one of the two chiral forms of the PT bond is resistant. To achieve complete protection against degradation at all PT bond positions, it is recommended to include five consecutive PT bonds in chemically synthesized DNA. Learn more here.

Tools & Resources

Selection Charts

Web Tools

FAQs & Troubleshooting

FAQs

  1. How can I remove the remaining primers and dNTPs from a PCR reaction prior to DNA sequencing?
  2. Can Thermolabile Exonuclease I remove primers in nested PCR reactions?
  3. Will Thermolabile Exonuclease I degrade RNA?
  4. Can Thermolabile Exonuclease I be used to blunt dsDNA?
  5. Can Thermolabile Exonuclease I be heat inactivated?
  6. Can Thermolabile Exonuclease I be used with a double-stranded exonuclease to clean up plasmid preparations?
  7. Will Thermolabile Exonuclease I work in other buffers?
  8. Can Exonuclease I be used with a double stranded exonuclease to clean up plasmid preparations?
  9. Can you tell me more about the switch from BSA to Recombinant Albumin (rAlbumin) in NEBuffers?

Quality, Safety & Legal

Quality Assurance Statement

Quality Control tests are performed on each new lot of NEB product to meet the specifications designated for it. Specifications and individual lot data from the tests that are performed for this particular product can be found and downloaded on the Product Specification Sheet, Certificate of Analysis, data card or product manual. Further information regarding NEB product quality can be found here.

Specifications

The Specification sheet is a document that includes the storage temperature, shelf life and the specifications designated for the product. The following file naming structure is used to name these document files: [Product Number]_[Size]_[Version]

Certificate Of Analysis

The Certificate of Analysis (COA) is a signed document that includes the storage temperature, expiration date and quality controls for an individual lot. The following file naming structure is used to name these document files: [Product Number]_[Size]_[Version]_[Lot Number]

Safety DataSheets

The following is a list of Safety Data Sheet (SDS) that apply to this product to help you use it safely.

Legal and Disclaimers

Products and content are covered by one or more patents, trademarks and/or copyrights owned or controlled by New England Biolabs, Inc (NEB). The use of trademark symbols does not necessarily indicate that the name is trademarked in the country where it is being read; it indicates where the content was originally developed. The use of this product may require the buyer to obtain additional third-party intellectual property rights for certain applications. For more information, please email busdev@neb.com.

This product is intended for research purposes only. This product is not intended to be used for therapeutic or diagnostic purposes in humans or animals.

New England Biolabs (NEB) is committed to practicing ethical science – we believe it is our job as researchers to ask the important questions that when answered will help preserve our quality of life and the world that we live in. However, this research should always be done in safe and ethical manner. Learn more.

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