The NEB(UK) website uses session and analytics cookies. By using this site you are agreeing to the use of cookies as described. Close Message
New England Biolabs UK Ltd NEB Technical Reference NEB Price List 2012 Free Delivery

Home > Products >Phusion® High-Fidelity DNA Polymerases and Kits


Phusion® High-Fidelity DNA Polymerases and Kits

Extreme Fidelity and Speed
Phusion® High-Fidelity DNA Polymerase offers robust performance for a wide range of templates. Its unique structure includes a novel Pyrococcus-like enzyme fused to a processivity-enhancing domain; this combination enhances fidelity, speed and overall performance. Reagent selection includes a standalone enzyme, master mix and kit format, as well as a choice of reaction buffers for amplification of difficult templates.
Phusion® Hot Start Flex DNA Polymerase is available as standalone enzyme or in a master mix format, and enables high specificity amplification of a broad range of templates. Phusion DNA Polymerase is a superior choice for cloning.
  • Extreme Fidelity - 50X greater than Taq
  • High Speed - Extension times are dramatically reduced (10X faster than Pfu).
  • Robust Reactions - Maximal success with minimal optimization.
  • High Yield - Increased product yield with minimal enzyme amount.
  • Versatility - Can be used for routine PCR as well as long or difficult templates.


Ordering InformationClick catalog number for specific product information
Notice to Customers:
Phusion® DNA Polymerase was developed by Finnzymes Oy, now a part of Thermo Fisher Scientific. This product is manufactured by New England Biolabs, Inc. under agreement with, and under the performance specifications of Thermo Fisher Scientific.
Please note that product numbers have changed, but pack sizes stay the same.
Please see our Phusion® Products FAQs for full information on changes.
For questions please contact NEB UK Technical Support: 0800 6522890 or
Two different buffers are provided with Phusion High-Fidelity DNA Polymerase and Phusion High-Fidelity PCR Kit. HF Buffer is the default buffer for most purposes and high-fidelity applications. GC Buffer can improve the performance of Phusion Polymerase on some difficult or long templates.
Phusion® High-Fidelity DNA Polymerase
M0530S100 units (2 units/l)
M0530L500 units (2 units/l)
Phusion® High-Fidelity PCR Master Mix with HF Buffer
M0531S100 reactions in 50 l volume
M0531L500 reactions in 50 l volume
Phusion® High-Fidelity PCR Master Mix with GC Buffer
M0532S100 reactions in 50 l volume
M0532L500 reactions in 50 l volume
Phusion® High-Fidelity PCR Kit
E0553S50 reactions in 50 l volume
E0553L200 reactions in 50 l volume
Buffers available separately
B0518S/LPhusion® HF Buffer Pack
B0519S/LPhusion® GC Buffer Pack
B0520S/LDetergent-Free Phusion® HF Buffer Pack
B0521S/LDetergent-Free Phusion® GC Buffer Pack
Phusion® Hot Start Flex DNA Polymerase
M0535S100 units
M0535L500 units
Phusion® Hot Start Flex 2X Master Mix
M0536S100 reactions in 50 l volume
M0536L500 reactions in 50 l volume
Extreme Performance
Getting the most out of your amplification reactions has always been difficult. Optimizing fidelity, specificity, and yield has been virtually impossible with a single enzyme. No longer is there a need to compromise performance. Phusion DNA Polymerase combines the fidelity you demand with speed and robustness. Incorporating a fusion protein technology developed by Finnzymes Oy in collaboration with MJ Bioworks, Inc, Phusion DNA Polymerase brings together a novel Pyrococcus-like enzyme with a processivity-enhancing domain. The Phusion DNA Polymerase generates PCR products with accuracy and speed previously unattainable with a single enzyme, even on your most difficult templates. 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® Technology

Most thermostable polymerases are not inherently processive. Generally they extend only few bases before falling off of the primed template. Due to this dissociative nature, even a short fragment requires numerous polymerase binding events to complete elongation. Inefficient or incomplete elongation results in an overall decrease in reaction efficiency and requires longer extension times and increased enzyme concentrations to ensure template completion. Polymerase performance is further challenged by long or difficult templates, resulting in lower yields and a higher rate of reaction failures.

By fusing a particular double-stranded DNA binding domain to the polymerase, its processivity can be increased 10-fold. Phusion DNA Polymerase exploits this dramatic increase in processivity, resulting in shorter extension times, more robust and high yield amplification, and the ability to amplify long templates in a fraction of the time.

Phusion Molecule
Figure 1. Phusion High-Fidelity DNA Polymerase schematic. The doublestranded DNA binding domain (orange) is fused with a novel Pyrococcus-like enzyme (yellow) forming a unique high performance polymerase.
Extreme Fidelity
The fidelity of Phusion DNA Polymerase is 50x higher than Taq DNA Polymerase and 6x higher than Pyrococcus furiosus DNA Polymerase.
Phusion Fidelity
Figure 2. Fidelity assays were performed using a
lacI-based method modified from Frey
& Suppman, 1995.
Extreme Yield
Phusion Yield
Figure 3. A 3.8 kb fragment was amplified from 50 ng of Jurkat gDNA using different polymerases. Reactions were carried out according to the manufacter's recommended conditions (cycling conditions are shown below). Extension times are indicated (in minutes). Ladder L is a 1 kb DNA Ladder.
Enzyme amounts/Cycling protocolsPhusion from NEB
High Fidelity
Accuprime Pfx
Enzyme amount1 unit2.5 units1 unit
Initial denaturation98C/30 s95C/2 min95C/2 min
Denaturation98C/10 s95C/30 s95C/30 s
Annealing59C/20 s45C/30 s50C/30 s
Extension (X)*72C/X min72C/X min68C/X min
Number of cycles303030
* X = 1 min, 1 min 30 s, 3 min 50 s and 7 min 40 s.
Phusion® Hot Start Flex DNA Polymerase

All amplicons are from human Jurkat template except for the 1.3 kb C. elegans amplicon. Amplicon sizes are indicated above gel. All reactions were conducted in duplicate according to manufacturer's instructions using 30 cycles and visualized after microfluidic LabChip® analysis.

tsClick here to access our Tm calculator.
Phusion is a trademarks of Finnzymes Oy, a Thermo Fisher Company.
PCR license notice: These products are sold under licensing arrangements of Finnzymes Oy with F.Hoffman- La Roche LTD, Roche Molecular Systems,Inc. and The Perkin-Elmer Corporation. The purchase of these products is accompanied by a limited license to use them in the Polymerase Chain Reaction (PCR) process in conjunction with a thermal cycler whose use in the automated performance of the PCR process is covered by the up-front fee, either by payment to Perkin-Elmer or as purchased, i.e. an authorized thermal cycler.
Notice to purchaser: Limited license. The purchase price of this product includes a limited, non-transferable license under U.S. and foreign patents owned by BIO-RAD Laboratories, Inc., to use this product. No other license under these patents is conveyed expressly or by implication to the purchaser by the purchase of this product.

Terms & Conditions | ISO Certification | Privacy | Returns | Delivery Conditions | Disclaimer | Contact Webmaster | NEB USA | NEB International | Cell Signaling Technology
Find NEB Online   hp youtube hp_twitter_icon Facebook     Find CST Online hp youtube hp_twitter_icon Facebook
©2002-2017, New England Biolabs (UK) Ltd