ENZYME-IMMUNOASSAY FOR THE DETERMINATION OF DOMOIC ACID IN MUSSEL EXTRACTS

A competitive enzyme immunoassay (ELISA) was developed for measuring t he concentration of domoic acid in extracts of mussel tissue. The assa y employed a polyclonal serum raised in mice against; an ovalbumin-dom oic acid conjugate. Spike-recovery experiments demonstrated that the c oncentration of domoic acid in both aqueous and acid extracts of musse l tissue could be accurately measured to within 8% of the actual value with the ELISA. The ELISA yielded accurate determinations at concentr ations as low as 0.25 mu g of domoic acid/mL of extract. Results of HP LC and ELISA analyses of sea mussel extracts correlated well (r = 0.96 ), although the ELISA resulted in higher values for domoic acid concen tration than the HPLC for most samples. This was partially attributed to a loss of domoic acid in the solid phase extraction prior to HPLC a nd to the possible presence of domoic acid isomers. It was concluded t hat a procedure such as the ELISA described herein would provide a use ful complement to the standard HPLC procedure currently employed in ro utine domoic acid analyses.