Long‐range PCR

Abstract

Abstract The polymerase chain reaction (PCR) has been used extensively in the amplification of DNA fragments where there is a general size preference for products less than 1000 bp. Larger products may be synthesized at low or inefficient levels and then normally after considerable effort in reaction optimization. While Taq DNA polymerase has remained the thermostable polymerase of choice for most PCRs, this enzyme is not efficient in the amplification of large DNA fragments. This limitation is thought to be due to the error‐prone nature of the Taq polymerase, whereby those transcripts that end in an error (a misincorporated base) are not efficiently reinitiated and extended. The combination of two thermostable DNA polymerases such as Taq and another enzyme with superior editing (proof‐reading) ability minimizes misincorporation and facilitates the amplification of long (reportedly over 40 kb) PCR products.