A HEMOLYTIC TEST TO ASSAY TOXINS EXCRETED BY THE MARINE DINOFLAGELLATE GYRODINIUM CF AUREOLUM

The haemolytic properties of phytoplankton toxins have been already demonstrated in many red tides. Although the detection of red blood cell (RBC) lysis is straightforward, it is not always easy to choose the most suitable type of RBC and incubation time. We have investigated these two points in order to obtain reproducible and quantifiable results, by applying the test to known haemolytic molecules. The dose-response curve is sigmoidal. The spiking technique allows a lowering of the detectable haemolytic threshold. Saponin and Kanagawa's haemolysin were used. Without previous concentration, the detection limit was at 4000 HU 1(-1). A chloroform-methanol extraction allowed the detection limit to be lowered to 0.1 HU 1(-1). This method has been applied to the detection of a marine dinoflagellate whose exotoxin is haemolytic. It may be used for in situ detection of any haemolytic substance.