Production and characterization of a monoclonal antibody against domoic acid and its application to enzyme immunoassay

For production of monoclonal antibodies against domoic acid, a causative ag ent of amnesic shellfish poisoning, three immunogens, domoic acid conjugate d with bovine serum albumin (BSA), ovalbumin (OVA) and human gamma globulin (HGG), were prepared. The antiserum obtained from BALB/c mice immunized wi th domoic acid-BSA showed the highest affinity for domoic acid. The monoclo nal antibody, DA-3, obtained from the mice was highly specific for domoic a cid and showed a minor cross-reactivity with the isomers of domoic acid (is odomoic acids B, E, F, G and H), except for isodomoic acid A. Using DA-3 an tibody, an indirect competitive enzyme immunoassay (idc-EIA) was developed for measurement of domoic acid. The working range for quantitative measurem ent of domoic acid and the quantification limit for domoic acid in shellfis h were estimated to be 0.15-10 ng/ml and less than 0.04 mu g/g, respectivel y. The mean recovery of domoic acid added to extracts of shellfish at toxin levels of 0.02 to 0.2 mu g/ml was 103% with a coefficient of variation of 4.5%. The newly developed idc-EIA seems to be a,useful method for monitorin g domoic acid in shellfish. (C) 1999 Elsevier Science Ltd. All rights reser ved.