COMPARISON OF A PROTEIN PHOSPHATASE INHIBITION ASSAY, HPLC ASSAY AND ENZYME-LINKED-IMMUNOSORBENT-ASSAY WITH THE MOUSE BIOASSAY FOR THE DETECTION OF DIARRHETIC SHELLFISH POISONING TOXINS IN EUROPEAN SHELLFISH

Consumption of shellfish contaminated with algal toxins produced by ma rine dinoflagellates can lead to diarrhetic shellfish poisoning (DSP). UK legislation necessitates toxin detection by mouse bioassay but thi s method is non-specific and lacks sensitivity. As an alternative meth od, an HPLC technique has been optimized, with detection limits of 0.2 6 mu g of toxin/g of shellfish hepatopancreas for both Okadaic Acid (O A) and Dinophysistoxin-1 (DTX-1). A colorimetric protein phosphatase i nhibition (PPI) assay has also been optimized. This assay detects inhi bition of protein phosphatase 1 (PPI gamma) by OA and DTX-1 with detec tion limits of 1.5 ng of total toxin/g of hepatopancreas. Contaminated shellfish from several European sources, the UK monitoring programmes and mussels associated with an outbreak of DSP poisoning in the UK, h ave been analyzed and assessed using the two alternative methods and a commercially available enzyme-linked immunosorbent assay (ELISA) kit. The results indicate that both the HPLC and PPI assays correlate well with each other and with the UK standard mouse bioassay. In contrast, and not withstanding its advantages of rapidity and ease, the ELISA k it did not accurately and consistently detect low toxin concentrations , although it may be useful as a screening tool. (C) 1997 Elsevier Sci ence B.V.