Comparative response of human and murine cell lines by cell bioassay to sodium channel active marine toxins and extracts

Flow Cytometric-Membrane Potential Detection of Sodium Channel Active Marine Toxins: Application to Ciguatoxins in Fish Muscle and Feasibility of Automating Saxitoxin Detection

“…All of the FRET response to depolarization occurs in the cell membrane itself, resulting in more rapid response to the membrane potential than achievable with DiSBac dyes and with less susceptibility to artifacts and background fluorescence (48). Attempts to improve performance of the assay should, however, always consider the critical role played by veratridine in the flow cytometric assay described here and in our site 5 cytotoxicity assays (12,13,49). Drug discovery schemes combining semiautomation with electrical stimulation and voltage-sensitive dyes (50) would likely fail in our application since veratridine synergism with ciguatoxins (12,13,49) would not be attainable.…”

“…Attempts to improve performance of the assay should, however, always consider the critical role played by veratridine in the flow cytometric assay described here and in our site 5 cytotoxicity assays (12,13,49). Drug discovery schemes combining semiautomation with electrical stimulation and voltage-sensitive dyes (50) would likely fail in our application since veratridine synergism with ciguatoxins (12,13,49) would not be attainable. Application of classical patch clamp experiments, especially automated forms proposed for microchip array-based patch clamp drug screening (51), are promising and might be modified to include application of veratridine, but it is unclear what level of sensitivity could be achieved.…”

“…A rapid assay format of our previously published antagonism assay for VGSC blocking studies (22) was performed by aspiration from a 96-well microplate (Becton Dickinson) using DiSBAC 2 [3]-equilibrated Neuro-2a cells as described above. Cell suspensions at 100 μL/well were first treated with a fixed concentration of veratridine (4 μM) for approximately 3 min to establish baseline fluorescence followed by an addition of STX to test wells.…”

An improved sensitive assay for the detection of PSP toxins with neuroblastoma cell-based impedance biosensor

“…Cell-based assay using continuous cell lines has undergone several enhancements since it was first established in 1988 (Kogure et al, 1988). The presence of PSP toxins can be detected by measuring the cell viability co-treated with ouabain and veratridine, which is a widely accepted cell-based assay today (Manger et al, 2003;Okumura et al, 2005).…”