PCR as Thermal Cycling

Thermal Cycle States

heat, cool, extend

PCR is controlled by a repeated thermal program before any copy-count arithmetic is claimed. Exact arithmetic here means exact results for the stated model inputs; measured inputs still carry uncertainty and significant-figure limits.

highlighted = computed this step

PCR is driven by a repeated thermal program

The diagram names the ideal stages. It does not claim real primer chemistry, enzyme kinetics, or exact laboratory temperatures.

denature→anneal→extend\text{denature}\rightarrow\text{anneal}\rightarrow\text{extend}
PCR thermal programNamed temperature stages are shown without numeric temperature claims.denatureannealextendheatcool

The program repeats before counting copies

The physics claim here is controlled thermal cycling. Exact copy counts come from the next ideal doubling model.

thermal cycle→ideal copy update\text{thermal cycle}\rightarrow\text{ideal copy update}
PCR thermal programNamed temperature stages are shown without numeric temperature claims.denatureannealextendheatcool

One ideal cycle has three named stages

The cycle template has one denature stage, one anneal stage, and one extend stage. The count is a stage count, not a temperature claim.

stagecount112131\begin{array}{c|c}\text{stage}&\text{count}\\1&1\\2&1\\3&1\end{array}
PCR thermal programNamed temperature stages are shown without numeric temperature claims.denatureannealextendheatcool