Tests of Two Fluorometric Assays for Gonyaulax and Aphanizomenon Toxins

摘要

The purpose of this research was to further test two assay procedures with shellfish extracts and with A. flos-aquae cells: a solution fluorometric assay and a column chromatography assay using Dowex AG-50W-X4, a sulfonic acid cation exchange resin, both developed by Shoptaugh. The assays were also tested to see if an inexpensive filter fluorometer could be used instead of the spectrofluorometer used in developing the assays. Attempts were also made to clean up the shellfish extracts by column chromatography in order to improve the sensitivity of the assay when used with the filter fluorometer. The research demonstrated that the solution fluorometric assay for PSP in shellfish gives results which are comparable to the mouse assay for shellfish of high toxicity and which are possibly more accurate than the mouse assay for shellfish of low toxicity. The assay, therefore, merits consideration for the routine monitoring of toxicity of shellfish. It was also shown that the assay was ineffective when a less expensive filter fluorometer was used in place of a spectrofluorometer. Attempts to modify the assay for use with a filter fluorometer were unsuccessful, but the problems encountered with the chromatographic clean-up of the extracts do not seem to be insurmountable. It is likely, therefore, that the assay could be adapted for use with a filter fluorometer. The column fluorometric assay appeared to be inapplicable to shellfish extracts, a finding which contradicts Shoptaugh's data. However, this assay did appear to be of some use when applied to extracts of the blue-green alga Aphanizomenon flos-aquae.