Complementary base pairing plays a role twice in RT-PCR, once when the cDNA is synthesized from mRNA and the second time when the cDNA is amplified by PCR. It plays a role in microarray analysis when the various probes bind to target DNA in the spots on the microarray based on complementary base pairing.
Work Step by Step
To see this, first look at Fig. 20.12 about RT-PCR: where you see double strands are the places when base pairing is important. Then see the text in that same area to read about the role of base pairing in the binding of DNA probes during the use of microarrays.