Identification of Gadoid Species in Fish Meat by Polymerase Chain Reaction (PCR) on Genomic DNA

• Published in: Journal of agricultural and food chemistry 2008-05, Vol.56 (10), p.3454-3459
• Main Authors: Hubalkova, Zora, Kralik, Petr, Kasalova, Janka, Rencova, Eva
• Format: Article
• Language: English
• Subjects: Analytical Methods; Animals; Biological and medical sciences; Codfish; conventional PCR; DNA - analysis; fish species identification; Fishes - classification; Fishes - genetics; food adulteration; Food Contamination - analysis; Food industries; Fundamental and applied biological sciences. Psychology; Gadiformes - classification; Gadiformes - genetics; Meat - classification; Meat and meat product industries; pantophysin I gene; Polymerase Chain Reaction; Sensitivity and Specificity; Species Specificity
• ISSN: 0021-8561; 1520-5118
• DOI: 10.1021/jf703684w

Identification of fish species is significant due to the increasing interest of consumers in the meat of sea fish. Methods focusing on fish species identification help to reveal fraudulent substitution among economically important gadoid species in commercial seafood products. The objective of this work was to develop a conventional PCR method for the differentiation of the following gadoid fish species in fish products: Alaska pollack (Theragra chalcogramma), blue whiting (Micromesistius poutassou), hake spp. (Merluccius spp.), Atlantic cod (Gadus morhua), saithe (Pollachius virens), and whiting (Merlangius merlangus). The species-specific primer pairs for gadoid species determination were based on the partial pantophysin I (PanI) genomic sequence. Sequence identification was confirmed by cloning and sequencing of the PCR products obtained from the species considered. For the simultaneous detection of Alaska pollack, blue whiting, and hake spp., a quadruplex PCR system was constructed. Other gadoid species were detected in separate PCR reactions. After optimization of the reactions, the developed PCR systems were used for the analysis of codfish samples obtained from the Czech market and the customsʼ laboratories. This method represents an alternative approach in the use of genomic DNA for the identification of fish species. This method is rapid, simple, and reliable without the need for further confirmative methods. Furthermore, the identification of a mixture of more than one species is possible. The PCR system has been optimized for routine diagnostic purposes.