As with many commercially available two-polymerase mixtures, a potential limitation of the TaqPlus Long PCR system is its relatively low fidelity compared to Pfu DNA polymerase (figure 1). The TaqPlus Long PCR system exhibits an error rate similar to Taq DNA polymerase, the predominant component in the TaqPlus Long polymerase mixture. To address the needs of researchers requiring both high yields of PCR product and high replication fidelity, Stratagene has added the TaqPlus Precison PCR system to its expanding line of PCR products.
Certain mixtures of proofreading and nonproofreading DNA polymerases have been shown to significantly increase PCR product yield and enhance amplification of longer targets compared to single-enzyme formulations.16-18 The enhanced performance of polymerase mixtures is presumably due to the capacity of one enzyme to complement the inability of a second enzyme to extend a primer through potential template obstructions. These potential obstructions include mispaired bases that cause nonproofreading polymerases to stall prematurely and disassociate from the primer-template,16 abasic gaps that cannot be bridged by polymerases lacking terminal transferase activity19 and template secondary structures20 such as GC-rich hairpins.
The TaqPlus Long PCR system was developed for PCR amplifications of long DNA
target regions (up to 35 kb) using relatively short extension times (0.5-1
minute per kb target). The system includes the TaqPlus Long DNA polymerase
mixture, consisting of Taq2000 DNA polymerase and cloned Pfu DNA
polymerases, and two reaction buffers. The low-salt buffer is recom