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  • Lambda Exonuclease

    cloned at neb recombinant unique buffer incubation temp heat inactivation
    Catalog #SizeConcentrationPriceQtyAdd to Cart
    M0262S1,000 units5,000 units/ml$65.00Add to Cart
    M0262L5,000 units5,000 units/ml$260.00Add to Cart
    Nuclease Products


    A highly processive enzyme that acts in the 5´ to 3´ direction, catalyzing the removal of 5´ mononucleotides from duplex DNA. The preferred substrate is 5´-phosphorylated double stranded DNA, although it will also degrade single-stranded and non-phosphorylated substrates at a greatly reduced rate. Lambda Exonuclease is unable to initiate DNA digestion at nicks or gaps (1).


    Isolated from a recombinant source
    Highly processive 5'→3' exonuclease
    Supplied in 10X Reaction Buffer

    Product Source

    A genetic fusion of the E. coli Lambda Exonuclease gene with the gene encoding maltose binding protein (MBP). Following affinity chromatography, Lambda Exonuclease is cleaved from the fusion construct and purified away from MBP.

    Reagents Supplied

    The following reagents are supplied with this product:

    Store at (°C)Concentration
    Lambda Exonuclease Reaction Buffer-2010X

    Properties and Usage

    Unit Definition

    One unit is defined as the amount of enzyme required to produce 10 nmol of acid-soluble deoxyribonucleotide from double-stranded substrate in a total reaction volume of 50 μl in 30 minutes at 37°C in 1X Lambda Exonuclease Reaction Buffer with 1 μg sonicated duplex [3H]-DNA.

    Reaction Conditions

    1X Lambda Exonuclease Reaction Buffer
    Incubate at 37°C

    1X Lambda Exonuclease Reaction Buffer:
    67 mM Glycine-KOH
    2.5 mM MgCl2
    50 μg/ml BSA
    pH 9.4 @ 25°C

    Usage Concentration

    5,000 units/ml

    Storage Temperature


    Storage Conditions

    25 mM Tris-HCl
    50 mM NaCl
    1 mM DTT
    0.1 mM EDTA
    50% Glycerol
    pH 8.0 @ 25°C

    Heat Inactivation

    75°C for 10 min

    Molecular Weight

    Theoretical: 28000 daltons

    Specific Activity

    50,000 units/mg

    Quality Control

    Quality Assurance Statement

    • Purified free of contaminating endonucleases and exonucleases.

    Quality Control Assays

    The following Quality Control Tests are performed on each new lot and meet the specifications designated for the product. Individual lot data can be found on the Product Summary Sheet/Datacard or Manual which can be found in the Supporting Documents section of this page.
    • Endonuclease Activity (Nicking, Buffer):
      The buffer is tested in a reaction containing a supercoiled DNA substrate. After incubation for 4 hours the percent converted to the nicked form is determined by agarose gel electrophoresis.


    1. Little, J.W. (1981). Gene Amplif. Anal. 2, 135-145.

    Supporting Documents

    Material Safety Datasheets

    The following is a list of Material Safety Data Sheets (MSDS) that apply to this product to help you use it safely. The following file naming structure is used to name these document files: [Product Name] MSDS. For international versions please contact us at info@neb.com.


    The Product Summary Sheet, or Data Card, includes details for how to use the product, as well as details of its formulation and quality controls. The following file naming structure is used to name the majority of these document files: [Catalog Number]Datasheet-Lot[Lot Number]. For those product lots not listed below, please contact NEB at info@neb.com or fill out the Technical Support Form for appropriate document.
    1. Can Exonuclease I be used with a double stranded exonuclease to clean up plasmid preparations?
    2. How Does T5 Exonuclease differ from Lambda Exonuclease (NEB# M0262)?
    3. How Does T7 Exonuclease differ from Lambda Exonuclease (NEB# M0262)?

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