Development of multiplex PCR for species-specific DNA determination of saury (Cololabis saira) and far eastern sardine, ivasi (Sardinops melanostictus)

The paper presents the development and validation of a multiplex real-time polymerase chain reaction (real-time PCR) method forspecies identification of canned products from saury ( Cololabis saira ) and Far Eastern sardine (Ivasi) ( Sardinops melanostictus ). The method is based on the use of the oligonucleotide system «Saury-Ivasi-VKO» and is aimed at solving the problem of adulteration of fish products, which is widespread in the Russian market. To assess the specificity of the method, a control panel of 90 fish species and 195 food fish samples were used. The method demonstrated high sensitivity, allowing detection of DNA of target species at up to 0.01% in the sample. The specificity of primers was confirmed by the absence of DNA amplification of unrelated species. The conducted experiments showed that the declared fish species were correctly identified in 100% of cases, and there were no false negative results. The results of food product testing revealed nonconformities in 34% of canned saury samples, of which 21 % were replaced by sardine and 6% by Pacific herring. The developed methodology reduces the cost of analysis due to the lack of dependence on imported reagents and can be implemented in laboratories working with GMOs and species identification. The conclusions confirm the effectiveness of the proposed approach for quality control and prevention of adulteration of fish products.