THE USE OF POLYCLONAL ANTISERA AND BLOCKING OF ANTIBODIES IN THE IDENTIFICATION OF MARINE DINOFLAGELLATES - SPECIES-SPECIFIC AND CLONE-SPECIFIC ANTISERA AGAINST GYMNODINIUM AND ALEXANDRIUM

Separate polyclonal antibodies were developed against cell surface antigens of the 4 dinoflagellate species: (a) Gymnodinium catenatum; (b) a morphologically similar non-toxic dinoflagellate Gyrodinium sp.; (c) Alexandrium minutum; and (d) morphologically similar A. lusitanicum. Blocking of antibodies to obtain clone-specificity were performed. Positive immunofluorescence reactions were visualized with epifluorescence microscopy as well as spectrofluorometry using FITC indirect immunofluorescence assay. Specificity and cross reactivity were tested with cells from laboratory cultures as well as cells from natural samples. Polyclonal antisera were species-specific (for G. catenatum and Gyrodinium sp.) and genus-specific (for Alexandrium). After blocking the antisera were clone-specific. An excellent labelling was obtained with fresh cells and from those preserved in 4% buffered formaldehyde. The blocking of the antibodies shows great promise as a technique to obtain clone-specific antisera.