A polyclonal antibody developed from Perkinsus marinus hypnospores fails to cross react with other life stages of P. marinus in oyster (Crassostrea virginica) tissues.

Polyclonal antiserum was produced from Perkinsus marinus hypnospores harvested from oyster tissue cultivated in fluid thioglycollate medium. The specificity of the antiserum for hypnospores was tested using indirect sandwich ELISA with alkaline phosphatase - conjugated goat anti-rabbit IgG and indirect immunofluorescence. As little as 20 ng. of hypnospore protein could be detected by ELISA. Immunofluorescence assays suggested that the antigenic material was a component of the spore cell wall. Cross-reactivity of the antiserum to other life stages of P. marinus present in oyster tissues could not be demonstrated by ELISA or immunofluorescence indicating that a substantial change in the antigenic properties of the cell wall occurs during spore formation. Hypnospore formation was also induced by placing P. marinus - infected oyster tissues into an anaerobic chamber rather than fluid thioglycollate. Spores were positively identified by ELISA, however little spore enlargement occurred suggesting that the triggering mechanism for spore formation is not the same as that for enlargement.