Evaluation of rapid methods for the determination of okadaic acid in mussels

Two different screening methods, a Buffalo Green Monkey cytotoxicity test and a biosensor test, have been considered to replace the of®cial mouse bioassay in monitoring for okadaic acid (OA) levels in mussels. Methods and Results: Diarrhoetic shell®sh poison-contaminated mussels from the Adriatic Sea were assayed in parallel by means of the mouse bioassay and both alternative methods. Both the cytotoxicity test and the biosensor test showed high sensitivity (OA 0á01 mg g±1 hepatopancreas and 0á002 mg g±1 hepatopancreas, respectively) and a high correlation with the mouse bioassay (r 0á932, P < 0á001 and r ) 0á850, P < 0á001, respectively). Conclusions: Both methods are ef®cacious, quick, inexpensive and provide data on the amount of toxin present in mussels. Signi®cance and Impact of the Study: Both methods, besides allowing the simultaneous assay of a great number of samples, comply with the ethical need to reduce the use of animals in the laboratory.