# Rapid Analysis of Pacific Ciguatoxins in Fish Extracts with a Lateral Flow Assay

## TL;DR

This paper introduces a fast and reliable test for detecting Pacific ciguatoxins in fish, which can help prevent poisoning in non-endemic regions.

## Contribution

The first lateral flow assay for detecting major Pacific ciguatoxin congeners using monoclonal antibodies.

## Key findings

- The LFA detects Pacific CTXs with a visual limit of 400 pg/mL and no cross-reactivity with other marine toxins.
- The assay successfully identified CTXs in both spiked and naturally contaminated fish samples.
- The test provides visual results in 30 minutes and is suitable for use in resource-limited settings.

## Abstract

The increasing spread of toxin-producing Gambierdiscus dinoflagellates has led to cases of ciguatera poisoning in previously
nonendemic regions. Ciguatoxins (CTXs) are potent, heat-stable compounds
responsible for ciguatera, and their rapid and reliable analysis in
seafood is essential to prevent illness. This study presents the development
of the first lateral flow assay (LFA) for the detection of major
Pacific CTXs congeners. The assay employs previously developed monoclonal
antibodies in a sandwich format: specific antibodies against CTX1B
and CTX3C are immobilized on a single test line, while the reporter
antibody is a single antibody recognizing major Pacific CTX congeners
that is conjugated to gold nanoparticles. The LFA provides one-step
visual results in 30 min, making it suitable for resource-limited
settings. It exhibits a visual limit of detection of 400 pg/mL and
the assay is highly specific, showing no cross-reactivity with other
marine toxins. It successfully detected Pacific CTXs spiked in noncontaminated
fish extracts, as well as in naturally contaminated samples as previously
confirmed by LC-MS/MS, with an estimated cutoff of approximately 0.1
μg/kg. Overall, this LFA demonstrates great potential as a rapid
screening tool for outbreak investigations and research programs.