Identification of channel catfish (Ictalurus punctatus) and basa (Pangasius bocourti) fillets by an enzyme linked immunoabsorbant assay using monoclonal antibodies and by fatty acid methyl ester analysis

The first objective of the study was to produce monoclonal antibodies (MAb) that would identify both channel catfish and basa fillets. A monoclonal antibody specific for a 36.8 kDa channel catfish (Ictalurus punctatus ) fillet protein was produced and characterized by indirect enzyme-linked immunoabsorbant assay (ELISA) and western blotting. Using the MAb clone 1A10 in the indirect ELISA, fillet proteins from Ictalurus sp. could be differentiated from non-Ictalurid fish fillet proteins. One hundred percent of Ictalurus fillets were correctly identified in a single blind study of both raw and cooked fillets. An additional MAb that was specific for a 71.6 kDa basa fillet protein was also developed. The MAb, clone 3F11, bound specifically to fillet proteins of the genus Pangasius in an indirect ELISA and correctly identified basa fillets in a single blind study. These results show that indirect ELISA using MAbs is a rapid and sensitive method for identification of channel catfish and basa fillets. The second objective of this study was to determine whether fatty acid analysis using software developed by MIDI (Newark, DE) was able to identify channel catfish fillets and differentiate from basa fillets. Ten samples of 25 mg frozen muscle from each species were processed to produce fatty acid methyl esters (FAME) and the fillet fatty acid profiles were used to create species-specific fillet libraries. The results show that the fatty acid profiles of basa are significantly different from those of channel catfish. The fatty acid fillet profiles for each species were highly reproducible when the same fillet was analyzed daily for three consecutive days. In a single blind study, 25 fillet samples from each species were assayed to identify the species of the fillet sample processed. The FAME method identified 25 of 25 (100%) basa fillet samples. Three out of 25 samples from channel catfish fillets were incorrectly identified as basa fillets. However, none of the basa fillets were identified as channel catfish fillets. (Abstract shortened by UMI.)...