Thermo Scientific™

Phusion U Hot Start PCR Master Mix

Catalog number:  F533S

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Thermo Scientific Phusion U DNA polymerase is a novel engineered high fidelity enzyme developed using fusion technology. Due to a proprietary mutation in the so called dUTP binding pocket of Phusion, Phusion U overcomes an important limitation of proofreading enzymes - it is able to incorporate dUTP and read through uracil present in DNA templates.

In addition to uracil usage possibility, Phusion U features all the superior properties of other Phusion DNA Polymerases - great accuracy, speed, ability to amplify long amplicons up to 20 kb and a high specificity with Affibody based hot start. These features make Phusion U Hot Start DNA Polymerase an excellent choice for such important applications as amplification of bisulphite-converted or damaged DNA as well as use of carryover contamination control.

Phusion U Hot Start PCR Master Mix is convenient 2X mix containing Phusion U Hot Start DNA Polymerase, nucleotides and optimized reaction buffer including MgCl2. Only template and primers need to be added by the user.


Accuracy—high fidelity DNA polymerase (25x Taq)
Uracil-tolerance —engineered to incorporate dUTP and amplify uracil containing templates
Specificity—hot start for reduced nonspecific amplification and primer degradation
Speed —short extension times (15-30 s/kb)


• Amplification of bisulphite-converted DNA
• Amplification of damaged or aged DNA
• Carry-over contamination control
• Uracil-excision based (USER) cloning methods

Using Phusion DNA Polymerases
Annealing rules for Phusion DNA Polymerases are different from many common DNA polymerases (such as Taq DNA polymerases). For optimal results, use our Tm calculator at

For Research Use Only. Not for use in diagnostic procedures.


Fidelity (vs. Taq): 25 X
GC-Rich PCR Performance: Medium
Hot Start: Built-In Hot Start
Overhang: Blunt
Polymerase: Phusion U Hot Start DNA Polymerase
Product Line: Phusion
Quantity: 100 x 50μL Reactions
Reaction Format: SuperMix or Master Mix
Reaction Speed: Fast

Contents & storage

Phusion U Hot Start PCR Master Mix includes:
• Phusion U Hot Start DNA Polymerase
• 2X reaction buffer
• 3 mM MgCl2
• 400 µM of each dATP, dTTP, dCTP and dGTP
The master mix is supplied with nuclease-free water.
Store at -20°C.