Protein Phosphatase Inhibition Assay for Detection of Diarrhetic Shellfish Poison in Oyster

A method based on protein phosphatase enzyme activity inhibition for monitoring diarrhetic shellfish poison (DSP) was used to analyze the DSP toxicity in three oyster samples. Based on the standard dose-effect curve developed with a series of okadaic acid (OA) standard solutions, the DSP toxicity of the three oyster samples collected was screened, and the results showed that OA and dinophysis toxins (DTXs) were not detected in the samples without hydrolyzation. However, the OA toxicity was detected in two of the hydrolyzed samples; the concentration of the OA was 1.81 and 1.21 μg OA eq./kg oyster, respectively.