High-fidelity PCR enzymes are used for applications requiring high accuracy during DNA amplification such as cloning, sequencing or mutagenesis. Thermo Scientific Phusion high-fidelity DNA polymerases were created by fusing a dsDNA-binding domain to a Pyrococcus polymerase–like proofreading enzyme. Due to this unique protein fusion engineering, Phusion DNA Polymerases have very low error rates, fast extension rates, and high inhibitor tolerance.

Select a Phusion DNA polymerase best suited for your application

Phusion high-fidelity DNA polymerases are available in a variety of formats. Please reference the table below to find an appropriate Phusion format for your application.

 NEWPhusion Plus DNA PolymerasePhusion High-Fidelity DNA Polymerase Phusion Hot Start II DNA PolymerasePhusion Flash High-Fidelity PCR Master MixPhusion U Hot Start DNA PolymerasePhusion U Multiplex PCR Master Mix
Fidelity (vs. Taq enzyme)>100x52x52x25x25x25x
Tm calculation requiredNoYesYesYesYesYes
Enhanced specificity (hot-start version)YesNoYesYesYesYes
Amplification lengthUp to 20 kbUp to 20 kbUp to 20 kbUp to 20 kb Up to 20 kbUp to 2.5 kb
Speed15–30 sec/kb15–30 sec/kb15–30 sec/kb<15 sec/kb15–30 sec/kb15–30 sec/kb
GC-rich formatYes (new GC enhanced)YesYesNoYesNo
dUTP incorporationNoNoNoNoYesYes
Designed for multiplex PCRNoNoNoNoNoYes, up to 20 targets
Stand-alone enzyme format*  
2x master mix format*

* All stand-alone enzymes are supplied with their reaction buffers. The 2x master mix formats include all necessary PCR components except the template and primers.
** Contains green loading dyes and a density reagent for direct gel loading of PCR products


Ordering information for Phusion high-fidelity DNA polymerases

Do you need a DNA polymerase with higher fidelity and/or performance than Phusion enzymes? Discover Invitrogen Platinum SuperFi II DNA Polymerasewith >300x Taq fidelity and a simplified PCR protocol.