PCR as Thermal Cycling

Double Each Cycle

ideal copy growth

In the early ideal model, each completed cycle doubles the number of copies. Exact arithmetic here means exact results for the stated model inputs; measured inputs still carry uncertainty and significant-figure limits.

highlighted = computed this step

Each ideal cycle doubles the count

Starting from 1 copy, 3 ideal cycles multiply by a power of 2.

N=Nstart⋅23N=N_{\text{start}}\cdot 2^{3}
PCR cycle ladderIdeal cycle stages are shown without claiming chemistry kinetics.copiesideal doubling

The copy count is exact

The final ideal count is 8 copies. Real PCR eventually saturates; this is an early-cycle model.

N=1⋅23=8N=1\cdot 2^{3}=8
PCR cycle ladderIdeal cycle stages are shown without claiming chemistry kinetics.copiesideal doubling

The copy count doubles one row at a time

The table unfolds the same ideal rule cycle by cycle.

cN01122438\begin{array}{c|c}c&N\\0&1\\1&2\\2&4\\3&8\end{array}
PCR cycle ladderIdeal cycle stages are shown without claiming chemistry kinetics.copiesideal doubling