qPCR Validation on the Basis of the Listeria monocytogenes prfA Assay

Quantitative real-time polymerase chain reaction (qPCR) is one of the most used molecular methods. There are numerous qPCR assays on the market, some of them for pathogen detection, and the development of new assays still continues. However, what methods are suitable for assay performance validation and which information do they provide? For conclusions based on qPCR data, it is essential to know which capacities and limitations an assay has. This chapter gives an overview of methods for qPCR assay performance validation and the respective insights and how to combine them. Most of those validation methods have been published in connection with the prfA assay, which specifically detects Listeria monocytogenes. Thereby, it could be demonstrated that this assay reliably quantifies even a single copy of the prfA gene and is thus suitable for detection of Listeria monocytogenes.