Feng, Xiaodong_ Xie, Hong-Guang - Applying pharmacogenomics in therapeutics-CRC Press (2016)

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DNA template
Primer
dNTP
DNA polymerase
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G allele
Denaturation
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TaqMan probe
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Sample A Partitioning Amplification
Sample B
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FIGURE 2.1 Illustration of polymerase chain reaction (PCR)–related methods. (a) A PCR
cycle generally includes denaturation, annealing, and elongation steps. (b) A representative
design for a tetra-primer set, which integrates allele-specific nucleotides into the 3′-ends
of primers. (c) A modified graph showing the mechanism of SNP genotyping by TaqMan
assay (Life Technologies) using allele-specific fluorophore-conjugated probes. The perfectly
matched TaqMan probe that anneals to the template will be degraded by DNA polymerase
and release the fluorescence (yellow), while the fluorophore (blue) of the mismatched TaqMan
probe that does not anneal will remain quenched. (d) Strategy of digital PCR to quantitatively
estimate the starting DNA templates. Sample A has fewer starting templates, which
are shown in fewer positive digital PCR reactions. For sample B, more starting templates are
shown in more positive digital PCR reactions.