TaKaRa Ex Taq HS is designed for hot start PCR; it includes a neutralizing monoclonal antibody that recognizes Taq DNA polymerase. This antibody inhibits polymerase activity by binding to Taq , thereby preventing nonspecific amplification due to mispriming and/or formation of primer dimers during reaction set-up before thermal cycling. Antibody-mediated repression is released during the initial DNA denaturation step of PCR. This enzyme can be used with standard PCR conditions. A hot-start version of Takara Ex Taq DNA polymerase, which combines the proven performance of Takara Taq polymerase with the proofreading activity of an efficient 3'-to-5' exonuclease, for high-sensitivity, high-efficiency PCR. Ex Taq is optimized for amplicons up to 20 kb from genomic DNA, and up to 30 kb from lambda DNA. Separate tubes of Mg2+ plus buffer and dNTP mix are supplied with the hot-start polymerase.