Authentication of Atlantic cod (Gadus morhua) using real time PCR.
This work describes the development of a real-time polymerase chain reaction (RT-PCR) system for the detection and identification of Atlantic cod (Gadus morhua). Among the advantages of this technique, it is worth highlighting that this is reliable in terms of specificity and sensitivity. The TaqMan real-time PCR is the simplest, fastest testing process and has the highest potential for automation, therefore representing the currently most suitable method for screening, allowing the detection of fraudulent or unintentional mislabeling of this species. The method can be applied to all kinds of products, fresh, frozen, and processed products, including those undergoing intensive processes of transformation. The developed methodology using specific primer-probe set was validated and further applied to 40 commercial samples labeled as cod in order to determinate if the species used for their manufacturing corresponded to G. morhua, detecting 20% that were incorrectly labeled. A C(t) value of about 19 was obtained when G. morhua was present. In samples with a species mixture, all samples that had a fluorescence signal were positive (C(t) < 30) for the presence of G. morhua by conventional end-point RT-PCR, and the estimated limit of detection for these type of samples was of 20 pg of DNA. The methodology herein developed is useful to check the fulfilment of labeling regulations for seafood products and verify the correct traceability in commercial trade and for fisheries control.
Herrero
Beatriz
B
Area of Molecular Biology and Biotechnology, ANFACO-CECOPESCA, Vigo, 36310 Pontevedra, Spain.
Madriñán
María
M
Vieites
Juan M
JM
Espiñeira
Montserrat
M
D000818:Animals; D001483:Base Sequence; D017931:DNA Primers; D015342:DNA Probes; D048389:Gadus morhua / Q000235:genetics*; D016133:Polymerase Chain Reaction / Q000379:methods*
D017931:DNA Primers; D015342:DNA Probes