Toxinological studies of the venom from Cassiopea xamachana nematocysts isolated by flow cytometry

The tentacle epithelial tissue of Cassiopea xamachana contains nematocysts and symbiotic algal particles. These two structures were dissociated, analy zed and sorted by flow cytometry. A simple separating method was developed utilizing the algal chlorophyll autofluorescence and the nematocysts' fluor escence after the uptake of fluorescent stains. A five-fold increase in mou se lethality; significantly more potent hemolytic and cytosensing activitie s; as well as a cleanup in the capillary electropherogram and SDS gel profi les for the crude nematocyst venom preparations prepared by fluorescence ac tivated cell sorting (FACS), was observed relative to alternative methods. Because the hemolytic potency of pre-sorting nematocyst venom was minimal a nd the post-sorting counterpart was significantly positive, the possibility that algae inhibited the venom's toxinological activity was considered. (C ) 2001 Elsevier Science Inc. All rights reserved.