Taq DNA Polymerase is a 94 kDa, thermostable, recombinant DNA polymerase obtained by expression of a modified form of the Thermus aquaticus (Taq) DNA polymerase gene in E. coli. It is the most thoroughly characterized enzyme available for PCR and its recombinant nature and purification method provide unparalleled purity and reproducibility. It has 5’- 3’ DNA polymerase activity but no 3’ -5’ exonuclease activity.