Viral diagnostics in the era of digital polymerase chain reaction

Unlike quantitative polymerase chain reaction (qPCR), digital PCR (dPCR) achieves sensitive and accurate absolute quantitation of a DNA sample without the need for a standard curve. A single PCR reaction is divided into many separate reactions that each have a positive or negative signal. By applying Poisson statistics, the number of DNA molecules in the original sample is directly calculated from the number of positive and negative reactions. The recent availability of multiple commercial dPCR platforms has led to increased interest in clinical diagnostic applications, such as low viral load detection and low abundance mutant detection, where dPCR could be superior to traditional qPCR. Here we review current literature that demonstrates dPCR's potential utility in viral diagnostics, particularly through absolute quantification of target DNA sequences and rare mutant allele detection.