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Thermo Scientific™ Phusion Hot Start II DNA Polymerase (2 U/µL)

Optimize PCR with one of the most accurate hot start DNA polymerases on the market, featuring extreme specificity and improved performance.

Manufacturer:  Thermo Scientific™ F549L

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Catalog No. F549L

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Phusion Hot Start II High Fidelity DNA Polymerase is the most accurate hot start DNA polymerase on the market. It combines the Phusion DNA Polymerase and a reversibly bound, specific Affibody ligand. Affibody inhibits the DNA polymerase activity at room temperature and thus prevents the amplification of nonspecific products.

The Affibody ligand also inhibits the 3´→5´ exonuclease activity of the polymerase, preventing degradation of primers and template DNA during reaction set up. At polymerization temperatures, the ligand is released, rendering the polymerase fully active. Phusion Hot Start II DNA Polymerase does not require a separate activation step in the PCR protocol as it is immediately reactivated at high temperatures.

New Phusion Green Hot Start II High-Fidelity DNA Polymerase is a combination of Phusion Hot Start II 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 Hot Start II DNA Polymerase and is compatible with downstream applications such as DNA sequencing, ligation and restriction digestion.

Phusion Hot Start High-Fidelity DNA Polymerase is a highly accurate hot start DNA polymerase. It has now been upgraded to allow the use of even wider range of primers, including those with low melting temperatures. The new Phusion Hot Start II DNA Polymerase is ideal for PCR applications from routine PCR to highly demanding applications such as cloning and high-throughput PCR.
  • No annealing temperature limitations
  • Allows reaction setup at room temperature
  • Zero-time reactivation due to unique hot start technology
  • Fast PCR enzyme with high fidelity (over 6 times more accurate than Pfu)
  • High product yields with low enzyme amounts gives excellent cost/reaction ratio
  • Robust enzyme with high tolerance against PCR inhibitors requires minimal optimization


5x Phusion HF Buffer, 5x Phusion GC Buffer, DMSO and 50mM MgCl2 solution. Both Phusion HF Buffer and Phusion GC Buffer provide 1.5 mM MgCl2 in the final 1x concentration

Recommended for:

Fast PCR, high-fidelity PCR, cloning, long or difficult amplicons, DHPLC, microarray



• Phusion Hot Start II High-Fidelity DNA Polymerase (2 U/µL)
• 5X Phusion HF Buffer
• 5X Phusion GC Buffer
• 50 mM MgCl2 solution
Both Phusion HF and GC Buffers provide 1.5 mM MgCl2 in the final 1X concentration.Store at -20°C.
52 X
Built-In Hot Start
Phusion Hot Start II DNA Polymerase
500U (2U/µL)
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Current Phusion Hot Start customers can switch to Phusion Hot Start II with no changes needed to existing protocols or primers. Original Phusion Hot Start will remain available for purchase, however, all new customers are advised to purchase Phusion Hot Start II to allow more flexibility in primer design.