HotStarTaq DNA Polymerase (250 U)

A modified form of Taq DNA Polymerase from QIAGEN provides high specificity in hot-start PCR. The enzyme is supplied in an inactive state and has no polymerase activity at ambient temperatures, preventing extension of nonspecifically annealed primers and primer–dimers formed during PCR setup and the initial PCR cycle. Activation requires a 15-minute incubation at 95°C, which can be incorporated into any existing thermal-cycler program.

The kit includes an innovative dual-cation PCR buffer, Q-Solution, and MgCl2. QIAGEN PCR Buffer maintains specific amplification in every cycle by promoting a high ratio of specific-to-nonspecific primer binding during the annealing step. A uniquely balanced combination of KCl and (NH4)2SO4 provides stringent primer-annealing conditions over a wider range of annealing temperatures and Mg2+ concentrations than conventional PCR buffers, minimizing the need for optimization. Q-Solution, also provided with the kit, facilitates amplification of difficult templates with high GC content or secondary structure by modifying the melting behavior of DNA, and is used at just one working concentration without compromising PCR fidelity.

Key specifications include a concentration of 5 units/µl, recombinant enzyme status, 5'→3' exonuclease activity, and extra A addition. The extension rate is 2–4 kb/min at 72°C, with a half-life of 10 min at 97°C and 60 min at 94°C, and amplification efficiency of ≥10⁵ fold. The enzyme has no 3'→5' exonuclease activity, no contaminating nucleases, RNases, or proteases, and no self-priming activity. Substrate analogs include dNTP, ddNTP, dUTP, biotin-11-dUTP, DIG-11-dUTP, and fluorescent-dNTP/ddNTP. The product is intended for single (not multiplex), endpoint PCR amplification with hot-start, as a standalone enzyme (not a mastermix), and is suitable for PCR, RT-PCR, complex genomic templates, and very low-copy targets, using genomic DNA or cDNA. The product should be stored at –30 to –15°C.