Application of an indirect ELISA and a PCR technique to detect grouper (Epinephelus marginatus) adulteration in the fish market

Overview & Synopsis

We have applied an indirect enzyme-linked immunosorbent assay (ELISA) and a multiplex polymerase chain reaction (PCR) procedure for the detection of grouper (Epinephelus marginatus) mislabelling in the fish market. An indirect ELISA (microtiter plates format) using two monoclonal antibodies (3D12 and 1A4) has been assayed in this study. Moreover, the multiplex PCR has been performed by using species-specific primers of the 5S rDNA gene for the rapid authentication of grouper. In this work, 70 commercial fish fillets samples collected from local markets and supermarkets, which were labelled as grouper, have been analysed by these techniques; 12 out of 70 samples confirmed to be grouper. PCR technique permitted the detection of the Nile perch (Lates niloticus) in the commercial fish fillets while it was not possible with the ELISA technique. Results suggested that both ELISA and PCR may provide specific and reliable tools for the detection of grouper adulteration, and an accurate implementation of the traceability for successful regulatory food controls.