FIGURE 1.

Droplet Digital PCR Method for specific detection of intact EHEC cells. Samples of food enrichment broths containing intact cells are added to the PCR reaction. A 20 μL PCR reaction is converted into 20,000 1 nL droplets prior to PCR-amplification. Amplification of eae (green) and stx (blue) is determined based on detection of fluorescent probes for each assay. In samples containing EHEC, both eae and stx targets will be detected in positive droplets. In samples containing mixtures of eae-negative STEC and eae-positive E. coli, most droplets will contain either eae or stx, unless both bacteria types are present within a single droplet.