Leatherhead Food Research PCR assay for horse DNA

Leatherhead Food Research has developed a real-time polymerase chain reaction (PCR) assay to detect the presence of horse DNA as an adulterant of fresh meat or of uncooked food products such as beef burgers.

The test utilises the European Union Reference Laboratory for Animal Proteins (EURL-AP) recommended protocol for detection of horse DNA using real-time PCR. Using the EURL-AP’s recommended sequence-specific primers and probes for horse mitochondrial DNA, an assay has been developed that reportedly has a limit of detection of approximately 0.01%.

A sample is considered positive at a level of 0.1% or above and an estimate of the percentage of horsemeat present in the sample can be provided by reference to an in-house standard. Multiple portions of each test sample are pooled to ensure that a representative sample is analysed.

Positive and negative samples are included in each assay, together with a control to check for adequate extraction of DNA from the sample and for any inhibition of the PCR reaction by components of the sample.