Clam extract assay

L/mole). It cross-reacts at >90% with saxitoxin but at <1% with neosaxitoxin. This antibody, when used in an anti-rabbit IgG "second antibody" radioimmunoassay format, can detect pmole quantities of saxitoxin. This assay has been shown to be a simple and efficient method for the analysis of saxitoxin in clam extracts. The lack of antibody cross-reactivity to the neosaxitoxin sub-group of the paralytic shellfish poisons limits the general utility of the assay to neurophysiology studies and to certain clam species which preferentially accumulate saxitoxin. However, the radioimmunoassay serves as a good precursor in the development of an enzyme immunoassay for the paralytic shellfish poisons. 

We employed various substrates to check for MFO in two bivalve species, a salt water mussel (Mytilus edulis) and a fresh water clam (Anodonta sp). Cytochrome P-450 was also studied. Organisms were exposed to 100 PPM Venezuelan crude in a stagnant system for up to one month. Enzyme assays were carried out with digestive gland 9000 g homogenates (17) and cytochrome P-450 analysis, with microsomes (21). The hydrocarbon substrates investigated included 1I+C-labelled benzo(a)pyrene, fluorene, anthracene, and naphthalene. The method used for separation of BP metabolites by thin layer radiochromatography has been described (7). The metabolite detection method for the other aromatic hydrocarbons was essentially the same except methylene chloride was used as metabolite extractant as well as TLC developer. Besides the hydrocarbon substrates, we also checked for other MFO reactions, N-dealkylase with C-imipramine (22) and 0-dealkylase with ethoxycoumarin (15). 

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