Differential toxicity of Physalia physalis (Portuguese man-o'war) nematocysts separated by flow cytometry

J. W. Burnett, J. V. Ordonez and G. J. Calton. Differential toxicity of Physalia physalis (Portuguese man-o'war) nematocysts separated by flow cytometry. Toxicon 24, 514 – 518, 1986. — Flow cytometric separation of Physalia physalis nematocysts resulted in isolation of the two previously reported sizes of organelles measuring 10.6 and 23.5 nm in diameter. The venom of the smaller nematocysts, which are present in greater abundance, was lethal in vitro to chick embryonic cardiocytes at doses of 0.6 μg protein/culture, whereas 20 μg protein prepared from the larger nematocysts was inocuous. SDS gel electrophoresis revealed common proteins of 69,000, 82,000 and 50,000 – 65,000 mol. wt in the nematocyst contents of both sizes of organelles.