Both the inlet and outlet of the PCR microchip were sealed with green septa rubbers (Thermogreen LB-2, Sigma-Aldrich, St. Louis, MO, USA) to prevent evaporation during PCR. A top cover with a cooling fan was then placed on top of the microchip (Figure 2A) and tightened by screws in order to tightly seal the microchip (Figure 2B). Thus, the entire microchip is enclosed inside a plastic casing, providing a dark environment to minimize background optical noise during fluorescence detection.