High-Fidelity PCR

High-fidelity polymerases for low-error PCR in cloning, mutagenesis, and sequencing workflows

When errors in your PCR product would compromise the downstream experiment, high-fidelity polymerases drop error rate to 10^-6 to 10^-7 per base through 3'-to-5' proofreading activity. You will reach for them for cloning, site-directed mutagenesis, NGS library prep, and any amplification where introduced mutations matter. Standard Taq and high-fidelity polymerases sit alongside each other: Taq for genotyping where errors are tolerable, high-fidelity for everything you plan to sequence or clone.

Work through what your template needs.

1. Fragment length. For routine fragments under 5 kb most high-fidelity polymerases work. For long products (5 to 30 kb) choose a long-PCR formulation.
2. GC content. For GC-rich templates (above 65 percent) choose GC-tolerant formulations.
3. Speed. For cycle-time-sensitive workflows choose fast-extension polymerases.
4. Direct-from-sample. For crude lysate input choose inhibitor-tolerant high-fidelity polymerases.
5. Master mix versus separate. For routine use 2X master mix; fewer pipetting steps means fewer errors. For unusual reaction conditions use separate components.

Meridian Life Science and Meridian (Bioline) carry MyFi, Velocity, and KAPA-equivalent formulations across the standard and long-PCR ranges. For cloning difficult inserts match enzyme to template on a small pilot before scaling; failed cloning is often a wrong-enzyme problem, not a wrong-protocol problem.