Taq DNA Polymerase is a thermostable protein isolated and purified from a recombinant E.coli strain containing Thermus aquaticus DNA Polymerase gene, with a molecular weight of about 90KD. It has 5'→3' polymerase activity and double-strand specific 5'→3' exonuclease activity, but no 3'→5' exonuclease activity. The Taq DNA Polymerase PCR product is a 3’ single A sticky end, which can be directly connected to the TA vector.