Flow cytometric detection of saxitoxins using fluorescent voltage-sensitive dyes

Area of Science:

• Neuroscience
• Toxicology
• Analytical Chemistry

Background:

• Saxitoxins are potent neurotoxins causing paralytic shellfish poisoning.
• These toxins block nerve cell depolarization, leading to toxic effects.
• Existing detection methods can be improved for sensitivity and real-time analysis.

Purpose of the Study:

• To develop and validate a sensitive method for saxitoxin detection.
• To utilize voltage-sensitive dyes and flow cytometry for enhanced assay performance.
• To demonstrate the method's efficacy with saxitoxin and crude shellfish extracts.

Main Methods:

• Cultured mouse neuroblastoma (Neuro 2a) cells were treated with voltage-sensitive fluorescent dyes.
• Veratridine was used to induce nerve cell depolarization.
• Saxitoxin's effect on fluorescence was measured using flow cytometry in real time.
• The most responsive cell population was selected to enhance assay sensitivity.

Main Results:

• Saxitoxin exposure resulted in a measurable decrease in nerve cell fluorescence.
• Flow cytometry allowed for real-time monitoring and selection of responsive cells.
• Preliminary studies confirmed the method's effectiveness with pure saxitoxin and shellfish extracts.

Conclusions:

• A novel, sensitive, and real-time method for saxitoxin detection has been established.
• The combination of voltage-sensitive dyes and flow cytometry offers a robust approach for toxin analysis.
• This method holds promise for the rapid assessment of paralytic shellfish poisoning risks.