Description_x000D_ Application_x000D_ Paralytic shellfish poisoning results from toxins originating primarily from algae of the genus Alexandrium causing intoxication and significant health risk for human consumers. This sample of porcine brain membrane homogenate is developed for use in receptor binding assays for determination of paralytic shellfish poisoning as described by Van Dolah et al. This assay provides a high throughput method for screening for paralytic shellfish poisoning and study of the receptors/toxins involved.