Fig. 1. Schematics of cLAMP colour change in the presence of the target of interest. (A) Top panel: Example of pH indicator and metal indicator colour change across time during amplification at 63 °C; Bottom panel: example of combining pH and metal indicator to obtain a new starting (negative, dark blue) and end colour (positive, green) during amplification. (B) Top panel: Schematics before amplification showing Mg²⁺ bounded to metal indicator (M) and free pH indicator; bottom panel: schematics after amplification showing free metal indicator, pH indicator bounded to H⁺ ions, and the byproduct pyrophosphate (PPi) which captures Mg²⁺ giving rise to Mg₂P₂O₇.