Fig. 3.

Chip performance at elevated temperatures. (A) Effect of incubation on droplet volume. Typical droplet-size distributions are shown before and after incubation at 65 °C for 70 minutes. The sample consisted of a negative control solution without template, hence no amplification was expected to occur. On average the droplets shrank by approximately 10%. As can be seen in the inset, the droplets located at the periphery of the array suffered from slightly increased shrinkage because they were more exposed to the bulk PDMS. Droplets in the center of the array were less affected by shrinkage. (B) Digital LAMP signature observed in our chipA section of the chamber array is shown before and after incubation. The intensity profile corresponds to a line across the centers of several chambers. Loop mediated DNA amplification in some of the chambers caused a sharp increase in their fluorescence. Neighbouring, non LAMP-competent chambers showed no increase in fluorescence, which demonstrated that sample crosstalk between adjacent chambers was negligible.