Multiplex fluorimetric assays for monitoring algal toxins

Abstract

Most known algal toxins act on ion channels either directly or indirectly, resulting in a change in intracellular ion concentrations when administered to targeted cells. The present project developed the working conditions for the use of fluorescent dyes in monitoring changes in membrane potential, intracellular calcium, and intracellular sodium levels in mammalian cell lines. Using these conditions, we were able to demonstrate specific changes in fluorescent signals in response to several purified toxins. We were also able to generate algal extracts which, when administered to the developed fluorimetric assays, were able to elicit different pattern of changes in membrane potential, intracellular calcium, and intracellular sodium levels. The differential pattern of responses induced by the different algal toxins in the three fluorimetric assays serve as a proof of concept for the use of multiplex fluorimetric assays in the laboratory monitoring of algal toxins.

Microwave cell lysis for ADDA‐ELISA analysis of total microcystins and nodularins

“…The World Health Organization's provisional guideline value is 1 μg/L MC-LR in drinking water. There is a diverse range of other biochemical and biological assays capable of being used for analyses of MCs, which include protein phosphatase inhibition assay (Carmichael & An, 1999), conventional and quantitative real-time polymerase chain reaction (Lu et al, 2020), microarrays/DNA chips (Rantala, Rizzi, Castiglioni, De Bellis, & Sivonen, 2008), fluorimetric assays (Mak, Yeung, Kwok, Wong, & Wong, 2009), and other alternative biosensors (Feng, Zhu, Wang, & Shi, 2014;Shi et al, 2013;Yu, Jang, Kim, Kim, & Kim, 2011). Total MCs can also be measured by analyzing 3-methoxy-2-methyl-4-phenylbutyric acid (MMPB, an oxidation product of microcystins) using LC/MS/MS or other analytical techniques (Duncan et al, 2018;Foss & Aubel, 2015).…”