Identification of goose (Anser anser) and mule duck (Anas platyrhynchos x Cairina moschata) foie gras by multiplex polymerase chain reaction amplification of the 5S rDNA gene

Polymerase chain reaction (PCR) amplification of the nuclear 5S rDNA gene h as been used for the identification of goose and mule duck foie gras. Two s pecies-specific reverse primers were designed and used in a multiplex react ion, together with a forward universal primer, to amplify specific fragment s of the 5S rDNA in each species. The different sizes of the species-specif ic amplicons, separated by agarose gel electrophoresis, allowed clear ident ification of goose and mule duck foie gras samples. This genetic marker can be useful for detecting fraudulent substitution of the duck liver for the more expensive goose liver.