Phusion High-Fidelity DNA Polymerase

Available On-Site

The most accurate thermostable DNA Polymerase available offering superior performance for cloning and other applications requiring high fidelity.

Phusion High-Fidelity DNA PolymeraseThermo Scientific Phusion DNA Polymerases set a gold standard for PCR performance. They offer a combination of characteristics that no other enzyme can match. Featuring an error rate 50-fold lower than that of Taq, and 6-fold lower than that of Pfu, Phusion DNA Polymerase is the most accurate thermostable polymerase available. This feature makes Phusion DNA Polymerases superior choice for cloning and other applications requiring high fidelity. The unique structure of the enzyme enables short protocol times, abundant yields and robust performance, even in the presence of PCR inhibitors. For the researcher, that translates to ease-of-use and convenience. In addition, Phusion DNA Polymerases also produce higher yields with lower enzyme amounts than other DNA polymerases.

New Phusion Green format is a combination of Phusion DNA Polymerase and 5X Phusion Green Buffers. The buffers include a density reagent and two tracking dyes for direct loading of PCR products on a gel. The colored buffer does not interfere with excelent performance of Phusion DNA Polymerases and is compatible with downstream applications such as DNA sequencing, ligation and restriction digestion.

Phusion High-Fidelity PCR Master Mixes are convenient 2X mixes designed to minimize the number of pipetting steps. Only template and primers need to be added by the user. Phusion High-Fidelity PCR Kit contains all the necessary reagents for PCR including control template and primers.

Phusion PolymerasesDID YOU KNOW?

The optimal annealing temperature for Phusion DNA Polymerases may differ significantly from that of Taq-based polymerases.

For optimal results start by accurately calculating your Tm with our Tm calculator.


  • Extreme fidelity (error rate 4.4 x 10-7 in Phusion HF Buffer)
  • Polymerase speed allows short extension times (15 to 30 s/kb)
  • Robust performance, minimal optimization needed
  • Increased product yields with minimal enzyme amounts
  • Direct loading on gel with Green Buffer


  • High performance PCR
  • High-fidelity PCR
  • Cloning
  • Sequencing (template generation)
  • High throughput
  • Difficult (GC-rich) templates
  • Template generation for sequencing
  • Long-range PCR
  • Cloning
  • Mutagenesis†
  • Microarray


Phusion High-Fidelity DNA Polymerase (F-530):

  • Phusion DNA Polymerase 2 U/μL
  • 5X Phusion HF Buffer
  • 5X Phusion GC Buffer
  • DMSO
  • 50 mM MgCl2 solution

Both Phusion HF Buffer and Phusion GC Buffer provide 1.5 mM MgCl2 in the final 1X concentration.

Phusion Green High-Fidelity DNA Polymerase (F-534):

  • Phusion DNA Polymerase 2 U/µL
  • 5X Phusion Green HF Buffer
  • 5X Phusion Green GC Buffer
  • DMSO
  • 50 mM MgCl2

Both Phusion Green HF and Phusion Green GC Buffer provide 1.5 mM MgCl2 in the final 1X concentration.

Phusion High-Fidelity PCR Master Mix with HF Buffer (F-531):

  • Phusion DNA Polymerase, 400 μM of each dNTP and 2X Phusion HF Buffer
  • DMSO

Phusion High-Fidelity PCR Master Mix with GC Buffer (F-532):

  • Phusion DNA Polymerase, 400 μM of each dNTP and 2X Phusion GC Buffer
  • DMSO

Master mixes provide 1.5 mM MgCl2 and 200 μM dNTP in final reaction concentration.

Phusion High-Fidelity PCR Kit (F-553):

  • Phusion DNA Polymerase 2 U/μl
  • 5X Phusion GC Buffer
  • 5X Phusion HF Buffer
  • dNTP mix (10 mM each)
  • MgCl2 solution (50 mM)
  • Control template (λ DNA)
  • 1.3 kb primers (4 μM each)
  • 10 kb primers (4 μM each)
  • DNA size standard
  • DMSO


Phusion Site-Directed Mutagenesis Kit also available.

Shelf Life0 Months,36 Months
Shipping ConditionDry Ice
Storage buffer20 mM Tris-HCl (pH 7.4 at 25 °C), 0.1 mM EDTA, 1 mM DTT, 100 mM KCl, stabilizers, 200 µg/mL BSA and 50 % glycerol.
Storage Condition-20 C
Fidelity comparison

Extreme fidelity for demanding PCR

Fidelity comparison

Relative fidelity values of different DNA polymerases. Phusion DNA Polymerases have extremely low error rates. The error rate, determined by a modified lacI-based method, is approximately 50-fold lower than that of Taq DNA polymerase and 6-fold lower than that of Pfu DNA polymerase. Fidelity = 1 / error rate.

gel images

Phusion DNA Polymerase combines extreme fidelity with unparalleled speed and robustness

gel images

A random set of 16 clones from a Thermus sp. genomic library was amplified from bacterial colonies. The results highlight the robustness and speed of Phusion DNA Polymerase. It was able to amplify 94% of the amplicons with lower enzyme amounts still producing superior yields. The success rate of Pfu DNA polymerase was only 56% and that of Taq DNA polymerase 62% with significantly lower yields.

gel image

Less enzyme - superior yield

gel image

A 3.8 kb fragment from human beta globin gene was amplified with three different DNA polymerases. Phusion DNA Polymerase was able to amplify the 3.8 kb genomic fragment with a combined annealing and extension step of only 1 minute, thus being significantly faster than the two other polymerases tested. A single unit of Phusion DNA Polymerase produced higher yields than 2.5 or 5 units of the Pfu DNA polymerases.

Agarose gel image showing enhanced yield of PCR products from 20 kb viral DNA and 7.5 kb genomic DNA templates using Phusion and Phusion Green proofreading DNA polymerases

Superior yields of long PCR products

Agarose gel image showing enhanced yield of PCR products from 20 kb viral DNA and 7.5 kb genomic DNA templates using Phusion and Phusion Green proofreading DNA polymerases

20 kb fragment from λ DNA and 7.5 kb fragment from human genomic DNA was amplified with Phusion and proofreading DNA polymerase from other suppliers. Phusion and Phusion Green DNA Polymerases were the only enzymes capable of providing high amounts of desired PCR products. In contrast, other proofreading polymerases delivered zero or significantly lower yields.

Agarose gel image showing high-yield amplicons produced from GC-enriched templates. A similar product from a competitor was unable to amplify from an 85% GC-enriched template while Phusion robustly amplified this template.

Robust amplification of DNA fragments regardless of GC content

Agarose gel image showing high-yield amplicons produced from GC-enriched templates. A similar product from a competitor was unable to amplify from an 85% GC-enriched template while Phusion robustly amplified this template.

Four DNA fragments of different GC content were amplified. Phusion Green DNA Polymerase produced all four amplicons with high yields. In contrast, competing high fidelity DNA polymerase was not able to efficiently produce GC-rich content.



Polymerase structure

  1. Y. Wang et al., A novel strategy to engineer DNA polymerases for enhanced processivity and improved performance in vitro. Nucleic Acids Research   32, 1197-1207 (2004).

  2. Wikman et al., Selection and characterization of HER2/neu-binding affibody ligands. Protein Eng Des Sel 17, 455-462 (2004).

  3. A. Guagliardi et al., The Sso7d protein of Sulfolobus solfataricus:in vitro relationship among different activities. Archaea 1, 87-93 (2002).

  4. Nord et al., Binding proteins selected from combinatorial libraries of an alpha-helical bacterial receptor domain. Nature Biotechnol 15, 772-777 (1997).


  1. B. Gilje et al., High-Fidelity DNA Polymerase Enhances the Sensitivity of a Peptide Nucleic Acid Clamp PCR Assay for K-ras Mutations. J Mol Diagn  10, 325-331 (2008).

  2. L. Meng et al., BEAMing up for detection and quantification of rare sequence variants. Nature Methods 3, 95-97 (2006).

  3. B. Frey, B. Suppmann, Demonstration of the Expend PCR Systems greater fidelity and higher yields with a lacI-based fidelity assay. Biochemica  2, 34-35 (1995).

PCR applications

  1. S. Qiu et. al., Nucleotide diversity in Silene latifolia autosomal and sex-linked genes. Proc R Soc B 277, 3283-3290 (2010).

  2. D. G. Gibson et al., Complete Chemical Synthesis, Assembly, and Cloning of a Mycoplasma genitalium Genome. Science 319, 1215-1220 (2008). [On Science website, see the Supporting Online Material for complete Materials and Methods section]

  3. Y. Zheng, R. J. Roberts, Selection of restriction endonucleases using artificial cells. Nucleic Acids Reserach 35, e83 doi: 10.1093/nar/gkm410 (2007).

  4. X. Shi, D.L. Jarvis, A new rapid amplification of cDNA ends method for extremely guanine plus cytosine-rich genes. Anal Biochem.  356, 222-228 (2006).

  5. J. Harholt et al., ARABINAN DEFICIENT 1 is a putative arabinosyltransferase involved in biosynthesis of pectic arabinan in Arabidopsis. Plant Physiol 140, 49-58 (2006).

  6. J. P. Balhoff, G. A. Wray, Evolutionary analysis of the well characterized endo16 promoter reveals substantial variation within functional sites. Proc Natl Acad Sci USA  102, 8591–8596 (2005).

  7. F. Delbos et al., Contribution of DNA polymerase eta to immunoglobulin gene hypermutation in the mouse. J Exp Med 201, 1191–1196 (2005).

  8. B. Dummitt et al., Yeast glutamine-fructose-6-phosphate aminotransferase (Gfa1) requires methionine aminopeptidase activity for proper function. J Biol Chem 280, 14356–14360 (2005).

  9. C. S. Fernandez et al., Rapid viral escape at an immunodominant simian-human immunodeficiency virus cytotoxic T-lymphocyte epitope exacts a dramatic fitness cost. J Virol 79, 5721–5731 (2005).

  10. S. Fiorucci et al., A FXR-SHP regulatory cascade modulates TIMP-1 and MMPs expression in HSCs and promotes resolution of liver fibrosis. J Pharmacol Exp Ther 314, 584-595 (2005).

  11. L. Fredriksson et al., Structural requirements for activation of latent platelet-derived growth factor-CC by tissue plasminogen activator. J Biol Chem 280, 26856–26862 (2005).

  12. M. Gauster et al., Endothelial lipase is inactivated upon cleavage by the members of the proprotein convertase family. J Lipid Res 46, 977–987 (2005).

  13. R. A. Hoskins et al., Rapid and efficient cDNA library screening by self-ligation of inverse PCR products (SLIP). Nucleic Acids Res  33, e185 (2005).

  14. N. Ivashikina et al., AKT2/3 subunits render guard cell K+ channels Ca2+ sensitive. J Gen Physiol 125, 483–492 (2005).

  15. S. M. Julio, P.A. Cotter, Characterization of the filamentous hemagglutinin-like protein FhaS in Bordetella bronchiseptica. Infect Immun 73, 4960-4971 (2005).

  16. G. I. Karras et al., The macro domain is an ADP-ribose binding module. EMBO J 24, 1911–1920 (2005).

  17. K. Moon et al., Regulation of excision genes of the Bacteroides conjugative transposon CTnDOT. J Bacteriol 187, 5732-5741 (2005).

  18. T. Nawy et al., Transcriptional profile of the Arabidopsis root quiescent center. Plant Cell 17, 1908–1925 (2005).

  19. Y. Noutoshi et al., ALBINO AND PALE GREEN 10 encodes BBMII isomerase involved in the histidine biosynthesis in Arabidopsis thaliana. Plant Cell Physiol 46, 1165–1172 (2005).

  20. G. Rizzo et al.The methyl transferase PRMT1 functions as co-activator of farnesoid X receptor (FXR)/9-cis retinoid X receptor and regulates transcription of FXR responsive genes. Mol Pharmacol 68, 551-558 (2005).

  21. M. V. Rockman et al., Ancient and recent positive selection transformed opioid cis-regulation in humans. PLoS Biol 3, e387 (2005).

  22. E. Rosonina et al., Role for PSF in mediating transcriptional activator-dependent stimulation of pre-mRNA processing in vivo. Mol Cell Biol 25, 6734-6746 (2005).

  23. P. O. Widlund, T.N. Davis, A high-efficiency method to replace essential genes with mutant alleles in yeast. Yeast 22, 769-774 (2005).

  24. R. Zhao et al., Identification of an acquired JAK2 mutation in polycythemia vera. J Biol Chem 280, 22788–22792 (2005).

  25. J. E. Collins et al., A genome annotation-driven approach to cloning the human ORFeome. Genome Biol 5, R84 (2004).

  26. M. W. Davis et al., A conserved metalloprotease mediates ecdysis in Caenorhabditis elegans. Development 131, 6001–6008 (2004).

  27. A. Ludwig et al., Molecular analysis of cytolysin A (ClyA) in pathogenic Escherichia coli strains. J Bacteriol 186, 5311–5320 (2004).

454 sequencing

  1. J. Y. Zhu et al., Identification of Novel Epstein-Barr Virus MicroRNA Genes from Nasopharyngeal Carcinomas. J Virol 83, 3333-3341 (2009).