Polymerases and Amplification Technologies
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  • Phusion Extreme Performance and Fidelity

    Return to Phusion® High-Fidelity DNA Polymerases

    Extreme Performance

    Phusion® High-Fidelity DNA Polymerase offers performance that no other enzyme can match. Getting the most out of your amplification reactions has always been difficult. Optimizing fidelity, specificity and yield has been challenging with a single enzyme. Phusion DNA Polymerase combines the fidelity you demand with unparalleled speed and robustness.

    Phusion DNA Polymerase brings together a novel Pyrococcus-like enzyme with a processivity-enhancing domain and generates PCR products from even your most difficult templates with accuracy and speed previously unattainable with a single enzyme. Additionally, Phusion DNA Polymerase is capable of amplifying long templates. In the quality control tests of Phusion DNA Polymerase, 7.5 kb genomic DNA and 20 kb λ DNA are routinely amplified. The unique structure and characteristics of Phusion DNA Polymerase make it a superior choice for cloning. The Phusion High-Fidelity DNA Polymerase sets a new standard for PCR performance.

    Phusion Hot Start Flex DNA Polymerase delivers additional flexibility to your reaction setup and cycling conditions. In contrast to chemically-modified or antibody-based hot start polymerases, Phusion Hot Start Flex utilizes an innovative synthetic aptamer. This structure binds to the polymerase through non-covalent interactions, blocking activity during reaction setup. The polymerase is activated during normal cycling conditions, allowing reactions to be set up at room temperature. Phusion Hot Start Flex does not require a separate high temperature incubation step, shortening reaction times and increasing ease-of-use. Phusion Hot start Flex is an ideal choice for high specificity amplification over a flexible range of annealing temperatures and offers robust amplification on a wide variety of templates.


    The fidelity of Phusion DNA Polymerase is >50x higher than Taq DNA Polymerase and 8.3x higher than Pyrococcus furiosus DNA Polymerase, making it the most accurate thermostable polymerase available.

    Click here to access our Tm calculator.

    Notice to Customers:

    Phusion DNA Polymerase was developed by Finnzymes Oy, now a part of Thermo Fisher Scientific. This product is now manufactured by New England Biolabs, Inc. under agreement with, and under the performance specifications of Thermo Fisher Scientific.

    Further details on this change can be found in the following customer communication. It is important to note that the catalog numbers for these products have changed. For any questions, please use our Phusion Request for Technical Support or call NEB Technical Support at 1-800-632-7799.