Marine biotoxins in seafood products are responsible for human illnesses and seafood production losses. Ciguatera poisoning (CP) is the most commonly reported non-bacterial seafood-related illness worldwide and is caused by the consumption of fish or shellfish containing ciguatoxins (CTXs), a class of polycyclic polyether marine biotoxins with highly complex chemical structures. Reliable laboratory testing in clinical samples for CTXs is not available and many analogues remain structurally unresolved. CTXs have a proposed backbone size of 3 nm but have never been directly observed. Herein, the first purported images of CTX-3C obtained by Cryogenic Electron Microscopy (Cryo-EM) and in the presence of gold nanoparticles with attached antibodies by Transmission Electron Microscopy (TEM) are presented. TEM image was captured based on a sample preparation optimization technique using anti-ciguatoxins CTX-3C [1C49] Ab00350-1.1 purified antibodies, gold nanoparticles, and a concentration of synthetic CTX-3C molecules combined for imaging. We discuss how other existing instrumentations with atomic resolutions exceeding <0.1 nm could be applied using this preparatory method to observe, with greater detail, the common backbone of all known CTXs and its proposed wider adoption towards other marine biotoxins. Conventional detection methods for marine toxins have drawbacks, applying cutting-edge existing technologies such as TEMs to directly observe never-before-seen marine toxins can contribute to the fundamental science of marine toxins research.

海产品中的海洋生物毒素是导致人类疾病和海产品生产损失的原因。雪卡中毒 (CP) 是全球最常见的非细菌性海鲜相关疾病，由食用含有雪卡毒素 (CTX) 的鱼类或贝类引起，雪卡毒素是一类具有高度复杂化学结构的多环聚醚海洋生物毒素。目前尚无法对 CTX 的临床样本进行可靠的实验室测试，并且许多类似物的结构仍未得到解决。CTX 的主干尺寸建议为 3 nm，但从未被直接观察到。在此，首次提出了通过低温电子显微镜 (Cryo-EM) 获得的 CTX-3C 图像，以及通过透射电子显微镜 (TEM) 在金纳米粒子与附着的抗体存在下获得的图像。基于样品制备优化技术捕获 TEM 图像，使用抗雪卡毒素 CTX-3C [1C49] Ab00350-1.1 纯化抗体、金纳米颗粒和一定浓度的合成 CTX-3C 分子组合进行成像。我们讨论了如何使用这种制备方法来应用原子分辨率超过 <0.1 nm 的其他现有仪器，以更详细地观察所有已知 CTX 的共同主干及其建议更广泛地采用其他海洋生物毒素。传统的海洋毒素检测方法存在缺陷，应用TEM等现有尖端技术直接观察前所未见的海洋毒素可以为海洋毒素研究的基础科学做出贡献。