The fidelity of DNA polymerases used in the polymerase chain reactions

Abstract

Abstract Purified DNA polymerases are one of the primary tools for molecular biology. Yet choosing the most appropriate DNA polymerase for any particular application requires an understanding of the substantial biochemical differences between the available enzymes. One aspect of interest for PCR is the fidelity of DNA polymerization, i.e. the number of errors produced per nucleotide synthesized. We begin this chapter by discussing the enzymology of error discrimination by DNA polymerases during DNA synthesis in vitro. We then describe the fidelity of several prokaryotic DNA polymerases using a simple assay for scoring DNA polymerase errors. Next we examine the parameters that affect the fidelity of the polymerase most often used for PCR, the Taq DNA polymerase isolated from Thermus aquaticus.