Figure 6.

Dependence of pre-PCR heating of PTE on primer dimer accumulation. Agarose gel analysis of primer dimer accumulation with preheated single OXP-modified primers in nontemplate system. Mixture of both primers was preheated at 95°C in 1× PCR buffer (pH 8.4 at 25°C) for increasing amounts of time. Samples were cooled on ice water, the Taq DNA polymerase was added followed by PCR amplification. PCR cycle parameters: 95°C (2 min); 30 cycles of [95°C (40 s); 56°C (30 s); and 72°C (2 min)]; 72°C (7 min). Primer dimer amplicon, indicated on the gel image, ran as a 50–80 bp DNA fragment (left lane: 50-bp ladder).