Flow cytometric analysis of cellular saxitoxin in the dinoflagellate Gonyaulax tamarensis var. excavata

Vast improvements in optics, electronics and stain utilization result in the ability to quantitatively analyze large numbers of cells (e.g. 10 ³–10 ⁶) of a population within minutes. Distribution of the saxitoxin content within a population of a variety of dinoflagellates, including Gonyaulax catenella, G. polyedra, G. monilata, G. tamarensis, G. excavata and G. tamarensis var. excavata, is highly variable, reflects cellular/environmental life history and age, and may be useful in chemotaxonomy. We demonstrate here the application of flow cytometry to the assaying of saxitoxin content in single cells of the New England red tide dinoflagellate G. tamarensis var. excavata.