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  • Taq 5X Master Mix


    Taq DNA Polymerase is a thermostable DNA polymerase that possesses a 5´→ 3´ polymerase activity (1,2,3) and a 5´ flap endonuclease activity (4,5).

    Taq 5X Master Mix is an optimized ready-to-use solution containing Taq DNA Polymerase, dNTPs, MgCl2, KCl and stabilizers. It is best for routine PCR applications from templates including pure DNA solutions, bacterial colonies, and cDNA. It can amplify up to 4 kb from complex genomic DNA or up to 5 kb from lambda DNA.

    Product Source

    An E. coli strain that carries the Taq DNA Polymerase gene from Thermus aquaticus YT-1.

    Reagents Supplied

    The following reagents are supplied with this product:

    Store at (°C)Concentration
    Magnesium Chloride (MgCl2) Solution-2025 mM

    Advantages and Features


    • PCR
    • Primer Extension
    • Colony PCR

    Properties and Usage

    Storage Temperature


    Buffer Composition

    10 mM Tris-HCl
    50 mM KCl
    1.5 mM MgCl2
    5% Glycerol
    0.08% IGEPAL® CA-630
    0.05% Tween® 20
    0.2 mM dNTPs
    25 units/ml Taq DNA Polymerase
    pH 8.6@25°C

    Heat Inactivation


    Unit Assay Conditions

    1X ThermoPol® Reaction Buffer, 200 µM dNTPs including [3H]-dTTP and 200 µg/ml activated Calf Thymus DNA.

    Unit Definition:

    One unit of Taq DNA Polymerase is defined as the amount of enzyme that will incorporate 10 nmol of dNTP into acid-insoluble material in 30 minutes at 75°C. 

    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.
    • Endonuclease Activity (Nicking):
      The product 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.
    • PCR Amplification (Master Mix):
      The polymerase master mix is tested in a polymerase chain reaction (PCR) using a control template and specific primers, resulting in the expected product.
    • Single Stranded DNase Activity (FAM Labeled Oligo):
      The product is tested in a reaction containing a fluorescent internal labeled single stranded oligonucleotide. The percent degradation is determined by capillary electrophoresis.


    1. Taq 5X Master Mix is stable for fifteen freeze-thaw cycles when stored at -20°C
    2. Taq 5X Master Mix is also stable for six months at 4°C, so for frequent use, an aliquot may be kept at 4°C.
    3. Taq 5X Master Mix should be used at a 1X concentration with DNA template and primers in a total reaction volume of 25 or 50 μl.


    1. Chien, A., Edgar, D.B. and Trela, J.M. (1976). J. Bact.. 127, 1550-1557.
    2. Kaledin, A.S., Sliusarenko, A.G. and Gorodetskii, S.I. (1980). Biokhimiya. 45, 644-651.
    3. Lawyer, F.C. et al. (1993). PCR Methods and Appl.. 2, 275-287.
    4. Longley, M.J., Bennett, S.E. and Mosbaugh D.W. (1990). Nucleic Acids Res.. 18, 7317-7322.
    5. Lyamichev, V., Brow, M.A. and Dahlberg, J.E. (1993). Science. 260, 778-783.
    6. Saiki R.K. et al. (1985). Science. 230, 1350-1354.
    7. Powell, L.M. et al. (1987). Cell. 50, 831-840.
    8. Sun, Y., Hegamyer, G. and Colburn, N. (1993). Biotechniques. 15, 372-374.
    9. Sarkar, G., Kapelner, S. and Sommer, S.S. (1990). Nucleic Acids Res.. 18, 7465.

    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. When should Taq DNA Polymerase be used in a primer extension reaction or for PCR?
    2. Why is the product a smear when visualized on an agarose gel?
    3. Why is there no product when visualized on an agarose gel?
    4. The product sequence doesn't completely match the expected sequence. How can this result be improved?
    5. Does the presence of Ca2+ inhibit PCR?
    6. What is the stability of Taq 5X Master Mix?
    1. Protocol for Taq 5X Master Mix (M0285)

    Selection Tools

    Usage Guidelines & Tips

    Troubleshooting Guides

    Interactive Tools

    Did you know most Taq reactions amplify more efficiently and robustly when you use a 68°C extension temperature?