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.

Find the right Phusion high-fidelity DNA polymerase format 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.