A Taq Polymerase For Every Occasion

Jane Lee, eENZYME’s director of marketing and sales, describes eENZYME’s anti-Taq monoclonal antibodies, whose key role is “to prevent the non-specific amplification and primer dimer formation.” They sell two types designed for hot start PCR amplification. “These antibodies have been widely used and tested by researchers for various PCR applications, including setting up personalized hot start reaction mixes, and setting up real-time hot start reaction ready mixes,” she adds. The company also sells their SupraTaq DNA Polymerase, for routine PCR applications, BioTherm Taq DNA Polymerase, a more robust Taq also for routine use, and Synergy Taq DNA Polymerase, for high fidelity amplification of long DNA with condensed GC-rich sequences.

Clontech offers a twist on the antibody-based hot start method. Their Titanium Taq DNA Polymerase includes the TaqStart antibody for hot-start advantages. In addition, Clontech has made an N-terminal deletion in their Titanium Taq, which eliminates the 5’-exonuclease activity of the enzyme, and makes it more soluble. They claim that this renders it more robust and sensitive, allowing you to use fewer PCR cycles with lower background, to amplify targets of up to 4 kb, and to amplify rare targets (even as few as two molecules in the starting reaction mixture, they claim). Titanium Taq also tolerates a wider range of magnesium concentrations than standard Taq, meaning less optimization for researchers.

USB Corporation takes a different approach to hot starts with their HotStart-IT FideliTaq DNA Polymerase. “Our new hot start method, called primer sequestration, uses a binding protein to reduce or eliminate non-specific primer-extension products, which may be generated at lower temperatures during assembly of PCR reactions,” explains Diane Petro, USB’s marketing communications manager. “Following the initial denaturation step during PCR, the binding protein is inactivated and the primers are free to participate in the amplification reaction. This novel hot start method enhances many complex PCR reactions by increasing specificity and yield.” For hot start PCR, USB also offers HotStart-IT Taq DNA Polymerase and Master Mix, and HotStart-IT FideliTaq DNA Polymerase and Master Mix.

QIAGEN’s Dirk Loeffert, director of research and development in modification and amplification, says that QIAGEN has “a novel hot start Taq polymerase, with a shortened reaction time to the hot start, which is compatible with a reaction buffe

Similarly, the dyes within QIAGEN’s new Fast Cycling PCR kit, CoralLoad Fast Cycling Dye, are red and orange—suitable for tracking DNA migration on an agarose gel. MIDSCI also offers their Bullseye Red Taq DNA Polymerase, which contains an inert red dye, so you can tell simply by looking at your tubes which reaction mixtures contain the Taq enzyme.

Promega also offers a color system to accompany its GoTaq DNA Polymerase. Their Green GoTaq Reaction Buffer contains two dyes (a blue dye and a yellow dye) that separate during gel electrophoresis, so you can monitor migration of your PCR products. Their Colorless GoTaq Reaction Buffer is also available for direct fluorescence or absorbance measurements before purification, or whenever the green buffer would interfere with downstream measurements.

For example, USB’s FideliTaq DNA Polymerase combines high quality USB recombinant Taq DNA Polymerase with a high-fidelity, proofreading polymerase. “This enzyme blend has the 5'-to-3' exonuclease activity of Taq DNA polymerase as well as the 3'-to-5' exonuclease activity of the proofreading polymerase,” says Petro. “FideliTaq DNA polymerase increases amplification fidelity up to six times over Taq DNA polymerase alone and allows for amplification of longer product sizes.”

Invitrogen offers “high fidelity” versions of its Platinum and AccuPrime Taq polymerases. The Platinum Taq DNA polymerase High Fidelity contains Taq polymerase, Pyrococcus species GB-D thermostable polymerase (a 3’-to-5’ exonuclease proofreading enzyme), and Platinum Taq antibody. Invitrogen claims that the pairing of Taq with the proofreading enzyme increases fidelity by approximately six times compared to that of Taq alone. Another benefit of this product is it enables amplification of a range of target template sizes: targets between 12 – 20 kb are possible with optimization, while targets greater than 20 kb are possible after thorough optimization. Invitrogen’s AccuPrime Taq DNA Polymerase High Fidelity combines an antibody-mediated hot-start version of Taq with the proofreading enzyme and AccuPrime accessory proteins. The latter work to enhance specific primer-template hybridization during PCR. This product gives a nine-fold higher fidelity compared to that of Taq alone, according to Invitrogen, and can amplify a range of targets efficiently up to 20 kb.

Stratagene combines Taq (their Taq2000 polymerase) with Pfu polymerase, another enzyme which by itself has a lower error rate but a longer extension time than Taq alone. The TaqPlus Precision PCR system is especially suited to applications involving high yields of PCR product and templates up to 15 kb, as well as other templates that were problematic with Taq alone. Likewise, Qbiogene’s Arrow Taq DNA Polymerase is a mixture of Taq and Tfu DNA polymerases, the latter of which has a lower error rate than Taq. Other advantages include: less template is needed than with Taq alone, and fragments up to 21 kb can be amplified.

If you need help optimizing your PCR reactions, or you simply aren’t sure which type of Taq polymerase you need, Invitrogen offers its PCR Enzyme Selection Kit-High Specificity, which is Taq-based, and its PCR Enzyme Selection Kit-High Fidelity, which contains another type of enzyme that you may choose. The high specificity kit is comprised of Platinum Taq DNA Polymerase, Platinum Taq DNA Polymerase High Fidelity, AccuPrime Taq DNA Polymerase, and Platinum PCR SuperMix (ready-to-use PCR mixture of Platinum Taq , salts, magnesium, and dNTP). “The latest PCR performance improvements can be experienced by using one of Invitrogen PCR Selection Kits. Each kit contains a unique sampling of four PCR reagents so that you can easily evaluate PCR enzymes for your new project or improve your current methods,” adds Keith Farnsworth, senior product manager for PCR at