Study of three red tide algae using immuno-fluorescent technique

To research and establish the qualitative and quantitative detection of red tide organisms via immunology and fluo rescence technique, polyclonal antibodies against three red tide algae with different size, Heterosigma akashiwo, Symnodinium sp.and Alexandrium catenella were raised.Block affinity treatment was done to enhance the specificity of the antibodies.The titer of three polyclonal antibodies was determined by the indirect enzyme-linked immunoso rbent assay, and three algal cells were detected by immuno-fluorescent technique.The result showed that Heterosigma akashiwo and Symnodinium sp.antibodies without block treatment got titer higher than 1:41 000 and 1:18 000, respectively, an indicating of high affinity antibodies.The titer of Alexandrium catenella antibody reached 1:3 500, relatively lower than the previous two.The specificity of three polyclonal antibodies after affinity treatment was raised remarkably.However, the titer declined.All the polyclonal antibodies showed a high affinity with their own cells.The fluorescent signal of Heterosigma akashiwo and Symnodinium sp.antibodies was conferred to the outer cell surface, while those of Alexandrium catenella was patchy distributed mainly around the excavated cingulum.Polyclonal antibodies were only reacted with their own algae.No cross activity with other two algae was detected.The antibody of Alexandrium catenella reacted its own cells, no cross activity was found with Alexandriumt amarense, which will be applicable in distinguishing species within the genus.Combining immunology with fluorescence technique had the advant ages of specific, sensitive, intuitionistic and simple with low cost.The development of the technique and methods will be prompted for the accurately qualitative and quantitative monitoring of red tide algae.