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 ant igens 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. Pos itive immunofluorescence reactions were visualized with epifluorescenc e microscopy as well as spectrofluorometry using FITC indirect immunof luorescence assay. Specificity and cross reactivity were tested with c ells from laboratory cultures as well as cells from natural samples. P olyclonal antisera were species-specific (for G. catenatum and Gyrodin ium sp.) and genus-specific (for Alexandrium). After blocking the anti sera were clone-specific. An excellent labelling was obtained with fre sh cells and from those preserved in 4% buffered formaldehyde. The blo cking of the antibodies shows great promise as a technique to obtain c lone-specific antisera.