Detection of grouper mislabelling in the fish market by an immunostick colorimetric ELISA assay

We have applied an immunostick colorimetric enzyme-linked immunosorbent assay (ELISA) assay for the rapid authentication of grouper (Epinephelus marginatus) fillets in the fish market. An indirect ELISA has been assayed by using a monoclonal antibody (3D12) developed previously in another work. In this study, 52 commercial fish fillets samples collected from local markets and supermarkets, which were labelled as grouper, have been analysed by this methodology; only 14 samples were confirmed to be grouper. The simplicity of the procedure and the short time required for the analysis make it suitable for a screening test of a large number of samples and it can be made into a field test for fish processors and inspectors to be used on site.