Long & Accurate PCR

References
1. Barnes, W. M. PCR amplification of up to 35-kb DNA with high fidelity and high yield from lambda bacteriophage templates. Proc. Natl. Acad. Sci. USA 91, 2216-2220 (1994).
2. Cheng, S., et al., Effective amplification of long targets from cloned inserts and human genomic DNA. Proc. Natl. Acad. Sci. USA 91, 5695-5699 (1994).

Many of today’s techniques demand longer amplifications and greater fidelity than standard Taq DNA polymerase can deliver. Applications such as genome analysis, cloning, sequencing, mutation analysis and protein expression, require not just PCR, but Long, High Fidelity PCR. Standard PCR using Taq DNA polymerase is generally limited to amplifications up to 5 kb. This is due in part to Taq DNA polymerase lacking a 3′→5′ exonuclease or “proofreading” activity, which repairs periodic misincorporations. After a misincorporation, the enzyme will either continue to incorporate nucleotides, causing a processive mistake or a terminal event will occur and elongation will be arrested.

Long and Accurate (LA) PCR is achieved by combining a highly processive thermostable polymerase with a second thermostable polymerase that exhibits a 3′→5′ exonuclease. This blending dramatically increases the length of amplification by using the proofreading polymerse to repair terminal misincorporations. This repair allows the polymerase to resume elongating the growing DNA strand.

AccuTaq™ LA and KlenTaq^® LA DNA Polymerase Mixes combine a high quality, highly processive polymerase with a small amount of a thermostable proofreading enzyme. The resulting enzymes mixes are capable of amplifying DNA targets from 0.25 to 40 kb, with an increase in fidelity from 4 to 6.5 times greater than standard Taq DNA polymerase.