For each cycle: mean signal during the in-chamber phase minus mean signal during the
out-of-chamber phase. This differential removes baseline drift and directly tracks
DNA amplification across cycles.
Cycle Overlay — all 40 cycles
Each line is one PCR cycle, aligned to the start of the in-chamber phase.
The dashed line marks the transition to the out-of-chamber dip (shaded right).
Colour transitions from faint (cycle 1) to solid (cycle 40).
Rising signal level across later cycles reveals DNA amplification.