Taq DNA Polymerase(a) is a thermostable enzyme of approximately 94 kDa isolated from Thermus aquaticus. This unmodified enzyme replicates DNA at 74°C and exhibits a half-life of 40 minutes at 95°C. The enzyme catalyzes the polymerization of nucleotides into duplex DNA in the 5´~3´ direction in the presence of magnesium and also possesses a 5´~3´ exonuclease activity. Taq DNA Polymerase is recommended for use in PCR but is not recommended for use in DNA sequencing reactions.