Identification of flatfish species using polymerase chain reaction (PCR) amplification and restriction analysis of the cytochrome b gene

Restriction site analysis of PCR products from a conserved region of the cytochrome b gene has been used for the specific identification of sole (Solea solea), European plaice (Pleuronectes platessa) and flounder (Platichthys flesus). Polymerase chain reaction (PCR) amplification of the cytochrome b gene using universal primers produced a 359 bp fragment in all species analyzed. Digestion of the PCR products with Ncil, Sau3Al and Hinfl endonucleases, followed by agarose gel electrophoresis of the digested PCR products, yielded specific profiles that enabled direct identification of the fish species. This methodology should prove useful for enforcing labeling regulations in the authentication of flatfish species