Digital polymerase chain reaction (dPCR) is emerging as a reliable platform for quantifying microorganisms in the field of health-related water microbiology. This paper reviews the fundamental principles of dPCR and its applications for health-related water microbiology. The relevant literature indicates increasing adoption of dPCR for measuring fecal indicator bacteria, microbial source tracking marker genes, and pathogens in various aquatic environments. The adoption of dPCR has accelerated recently due to increasing use for wastewater surveillance of SARS-CoV-2 the virus that causes COVID-19. The collective experience in the scientific literature indicates that well-optimized dPCR assays can quantify genetic fragments of microorganisms without the need for a calibration curve and often with superior analytical performance (i.e., greater sensitivity, precision, and reproducibility) than quantitative polymerase chain reaction (qPCR). Nonetheless, dPCR should not be viewed as a panacea for the fundamental uncertainties and limitations associated with measuring microorganisms in health-related water microbiology. With dPCR platforms, the sample analysis cost and processing time typically are greater than qPCR. However, if improved analytical performance (i.e., sensitivity and accuracy) is required, dPCR can be an alternative option for quantifying microorganisms, including pathogens, in aquatic environments.
Application of digital PCR for public health-related water quality monitoring