Platinum® Taq DNA Polymerase is recombinant Taq DNA polymerase complexed with a proprietary antibody that blocks polymerase activity at ambient temperatures. Activity is restored after the denaturation step in PCR cycling at 94°C, thereby providing an automatic “hot start” for Taq DNA polymerase in PCR (1,2,3). Hot starts in PCR provide increased sensitivity, specificity, and yield, while allowing assembly of reactions at room temperature. The use of this antibody helps reduce PCR optimization requirements, reaction set-up time and effort, handling of reaction components, and contamination risk. Like standard Taq DNA Polymerase, Platinum® Taq has a nontemplatedependent terminal transferase activity that adds a single deoxyadenosine (A) to the 3' ends of PCR products. Like standard Taq, it has both 5' → 3' polymerase and 5' → 3' exonuclease activity, but lacks 3' → 5' exonuclease activity. Platinum® Taq is supplied at the same 5 unit per μL concentration as Taq DNA Polymerase. No modification to PCR reactions or protocols are necessary. This enzyme formulation can also be used in larger volume cocktail mixes without difficulty.