Faster is BetterWhen PCR is performed rapidly, the quality of PCR products is often better. Back in 1990, we were amplyfing PCR products of 500 bp in about 15 min. This was accomplished by using little or no holds at extension, denaturation or annealing temperatures. Advancement in instrumentation and technology now allows even faster PCR.
Figure on the right shows a gel image of PCR products overlaid with temperature traces from the amplification that generated each of the products - more specific product is generated with faster PCR. (Click image to enlarge)