The classical in vitro genotoxicity test battery is known to be sensitive for indicating genotoxicity. However, a high rate of ‘misleading positives’ was reported when three assays were combined as required by several legislations. Despite the recent optimisations of the standard in vitro tests, two gaps could hardly be addressed with assays based on 2D monolayer cell cultures: the route of exposure and a relevant intrinsic metabolic capacity to transform pro-mutagens into reactive metabolites. Following these considerations, fertilised chicken eggs have been introduced into genotoxicity testing and were combined with a classical read-out parameter, the micronucleus frequency in circulating erythrocytes, to develop the hen’s egg test for micronucleus induction (HET-MN). As a major advantage, the test mirrors the systemic availability of compounds after oral exposure by reflecting certain steps of Absorption, Distribution, Metabolism, Excretion (ADME) without being considered as an animal experiment. The assay is supposed to add to a toolbox of assays to follow up on positive findings from initial testing with classical in vitro assays. We here report on a validation exercise, in which >30 chemicals were tested double-blinded in three laboratories. The specificity and sensitivity of the HET-MN were calculated to be 98 and 84%, respectively, corresponding to an overall accuracy of 91%. A detailed protocol, which includes a picture atlas detailing the cell and micronuclei analysis, is published in parallel (Maul et al. Validation of the hen’s egg test for micronucleus induction (HET-MN): detailed protocol including scoring atlas, historical control data and statistical analysis).

中文翻译：

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鸡蛋微核诱导试验 (HET-MN)：验证数据集


众所周知，经典的体外遗传毒性测试电池对于指示遗传毒性非常敏感。然而，当按照多项立法的要求组合三种检测方法时，“误导性阳性结果”的发生率很高。尽管最近对标准体外测试进行了优化，但基于 2D 单层细胞培养物的测定很难解决两个差距：暴露途径和将促诱变剂转化为反应性代谢物的相关内在代谢能力。考虑到这些因素，受精鸡蛋已被引入遗传毒性测试，并与经典的读出参数（循环红细胞中的微核频率）相结合，开发了用于微核诱导的鸡蛋测试（HET-MN）。该测试的一个主要优点是，通过反映吸收、分布、代谢、排泄 (ADME) 的某些步骤，反映了口服暴露后化合物的全身可用性，而不被视为动物实验。该测定应该添加到测定工具箱中，以跟踪经典体外测定初始测试的阳性结果。我们在此报告一项验证活动，其中 >30 化学品在三个实验室进行了双盲测试。 HET-MN 的特异性和敏感性经计算分别为 98% 和 84%，相当于总体准确度为 91%。详细的方案，其中包括详细介绍细胞和微核分析的图片图集，已同时发布（Maul 等人。微核诱导母鸡鸡蛋测试的验证 (HET-MN)：详细的方案包括评分图集、历史控制数据和统计分析）。