Low Level Pathogen Detection Using Digital PCR
Precise pathogen detection in the presence of inhibitors
Detection of low-level pathogens is important in situations where bacterial or viral pathogens cause human illnesses, often through contaminated food or water supplies. In this context, it is important to detect pathogens in the food chain at the earliest opportunity to reduce their impact. While real-time PCR (qPCR) can be a useful tool for pathogen detection in general, it is sensitive to PCR inhibitors present in the crude samples common to food and water testing.
By contrast, digital PCR is less sensitive to inhibitors and offers a more robust testing platform. It works by partitioning each sample into thousands of independent, parallel PCR reactions. Digital PCR is not as easily affected by inhibitors than real-time PCR, because it is an endpoint reaction, and as such it is possible to more accurately and precisely measure pathogen concentration in what would be an otherwise highly inhibited sample. In addition, digital PCR provides an absolute count of pathogenic sequences, eliminating the need for reference material or a standard curve.
Measuring the absolute number of molecules in a biological sample is a relatively common need. But, this can pose some unique challenges when using standard real-time PCR. In contrast, digital PCR is not dependent on cycle thresholds or references, yielding a simple and precise method to obtain absolute quantification
Deborah Grove, PhD, Director - Genetic Analysis, Genomics Core Facility at The Huck Institutes of the Life Sciences Penn State University Park, Pennsylvania
For Research Use Only. Not for use in diagnostic procedures.