DETERMINATION OF OKADAIC ACID CONTENT OF DINOFLAGELLATE CELLS - A COMPARISON OF THE HPLC-FLUORESCENT METHOD AND 2 MONOCLONAL-ANTIBODY ELISATEST KITS

Total okadaic acid (okadaic acid plus methylokadaic acid) in acclimate d clones of the dinoflagellates Prorocentrum hoffmannianum and P. lima was determined using the HPLC-fluorescent method, UBE ELISA test kit, and Rougier ELISA test kit. The nonokadaic acid-producing species, Am phidinium klebsii, Prorocentrum mexicanum, P. micans, PT cassubicum, a nd Gambierdiscus toxicus were examined using the same methods of analy sis. All three methods yielded consistent results for P. hoffmannianum which produces only okadaic acid. However, results of the three metho ds were not consistent for P. lima which produces both okadaic acid an d methylokadaic acid. The UBE ELISA demonstrated little or no cross-re activity with methylokadaic acid; whereas, the Rougier ELISA demonstra ted varying degrees of cross-reactivity with that analog. Analyses of nonokadaic acid producing-species yielded negative results, with one e xception. The Rougier ELISA demonstrated reactivity with extracts of G . toxicus. Since outbreaks of DSP may be caused by okadaic acid, methy lokadaic acid, or a combination of these toxins, both ELISA kits may u nderestimate total toxin present in toxic shellfish. Copyright (C) 199 6 Elsevier Science Ltd