Abstract

Digital PCR in the Clinical Virology Laboratory - Applications and Limitations

Keith Jerome, Professor, University of Washington

Digital PCR offers several theoretical advantages over qPCR that suggest it might prove useful in clinical virology laboratories. We have evaluated the Bio-Rad droplet digital PCR system in a number of diagnostic virology applications. These studies confirm the extreme precision of dPCR quantitation, and also reveal that dPCR is more resistant to inhibition than traditional qPCR. The precision of dPCR is especially useful in ratiometric assays, such as for the diagnosis of chromosomally integrated HHV-6. Conversely, for many applications such as cytomegalovirus quantitation, we have been unable to demonstrate clinical utility of the improved precision over qPCR. Precise quantitation of virus may be more useful at this point in research studies, such as evaluation of the HIV reservoir during eradication efforts. Finally, the current early generations of dPCR instrumentation have substantially lower throughput than the more mature qPCR platforms, suggesting that widespread replacement of qPCR by dPCR is at this point premature.