Investigating CSI – Background material Table of Contents I ...

2. cDNA is denatured at more than 90 degrees (~94 degrees) so that the
two strands separate. The sample is cooled to 50 to 60 degrees and
specific primers are annealed that are complementary to a site on each
strand. The primers sites may be up to 400 bases apart but are often
about 100 bases apart, especially when real-time PCR is used.
3. The temperature is raised to 72 degrees and the heat-stable Taq DNA
polymerase extends the DNA from the primers. Now we have four cDNA
strands (from the original two). These are denatured again at
approximately 94 degrees.
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