• My NEB
  • Print
  • PDF
  • TaqI Methyltransferase


    TaqI Methyltransferase modifies the adenine residue (N6) of the sequence TCGA.

    Product Source

    An E. coli strain that carries the cloned TaqI modification gene from Thermus aquaticus.

    Reagents Supplied

    The following reagents are supplied with this product:

    Store at (°C)Concentration
    NEBuffer 4-2010X
    BSA-2010 mg/ml
    S-adenosylmethionine (SAM)-2032 mM

    Properties and Usage

    Unit Definition

    One unit is defined as the amount of enzyme required to protect 1 μg λ DNA in 1 hour at 65°C in a total reaction volume of 20 μl against cleavage by TaqI restriction endonuclease.

    Reaction Conditions

    1X NEBuffer 4
    Supplement with 80 μM S-adenosylmethionine (SAM) and 100 μg/ml BSA
    Incubate at 65°C

    1X NEBuffer 4:
    50 mM Potassium Acetate
    20 mM Tris-acetate
    10 mM Magnesium Acetate
    1 mM DTT
    pH 7.9 @ 25°C

    Protection Assay Conditions:
    TaqI Methyltransferase is incubated with 1 µg λ DNA in 20 µl 1X NEBuffer 4, 100 µg/ml BSA and 80 µM S-adenosylmethionine, for 1 hour at 65°C. The extent of protection by TaqI Methyltransferase is determined by the addition of 30 µl 1X NEBuffer 4 and 10 units of TaqI restriction endonuclease. Incubation for 1 hour at 65°C is followed by analysis on an agarose gel.

    Storage Temperature


    Storage Conditions

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

    Molecular Weight

    Theoretical: 47845 daltons

    Quality Control

    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.
    • Exonuclease Activity (Radioactivity Release):
      The product is tested in a reaction containing a radiolabeled mixture of single and double-stranded DNA. After incubation for 4 hours the exonuclease activity is determined by the % release of radioactive nucleotides.
    • Non-Specific DNase Activity (16 hour):
      The product is tested for non-specific nuclease degradation in a reaction containing a DNA substrate. After incubation for 16 hours there is no detectable degradation of the DNA substrate as determined by agarose gel electrophoresis.


    1. TaqI Methyltransferase gives 25% activity at 37°C.


    1. Hoffman, J.L. (1986). Biochemistry. 25, 4444-4449.

    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. Is S-adenosylmethionine (SAM) supplied with the Methyltransferase?
    2. What should be considered if the methylation is not going to completion?
    3. What is the activity of TaqI Methyltransferase at 37°C?
    4. What is the activity of TaqI Methyltransferase at 50°C?
    5. Does TaqI Methyltransferase require MgCl2?
    6. Does TaqI Methyltransferase require BSA?
    7. What is the activity of TaqI Methyltransferase in other buffers?
    8. What is the molecular weight of TaqI Methyltransferase?
    9. Is TaqI Methyltransferase used in any special techniques?