Identification of commercial fish species belonging to the orders Pleuronectiformes and Gadiformes: Library of isoelectric focusing patterns

Isoelectric focusing in polyacrylamide gel was used to establish an identif ication archive of fish species belonging to the orders Pleuronectiformes, or flat fish, and Gadiformes, or gadoid fish. The 2 orders include species of different commercial value and interest that are frequently requested in European fish markets, but are susceptible to substitution either because they are morphologically similar or because they arrive on the markets alre ady filleted or sliced. The sarcoplasmic protein profiles are species-speci fic and reproducible. The use of densitometry and image analysis coupled wi th a simple computer program overcomes the subjective evaluation of the pat terns, making it possible to identify species correctly.