The muscle-relaxing effects of the botulinum neurotoxin (BoNT) serotypes A and B are widely used in clinical and aesthetic medicine. The standard method for measuring the biological activity of pharmaceutical BoNT products is a mouse bioassay. In line with the European Directive 2010/63/EU, a replacement by an animal-free method would be desirable. Whereas the existing approved in vitro methods for BoNT activity measurements are product-specific and not freely available for all users, the “binding and cleavage” (BINACLE) assay could become a widely applicable alternative. This method quantifies active BoNT molecules based on their specific receptor-binding and proteolytic properties and can be applied to all BoNT products on the European market.

Here we describe the results of a transferability study, in which identical BoNT samples were tested in the BINACLE assay in four laboratories. All participants successfully performed the method and observed clear dose-response relationships. Assay variability was within an acceptable range. These data indicate that the BoNT BINACLE assay is robust and can be straightforwardly transferred between laboratories. They thus provide an appropriate basis for future studies to further substantiate the suitability of the BINACLE assay for the potency determination of BoNT products.

肉毒杆菌神经毒素 (BoNT) 血清型 A 和 B 的肌肉松弛作用广泛用于临床和美容医学。测量药物 BoNT 产品生物活性的标准方法是小鼠生物测定。根据欧洲指令 2010/63/EU，最好用无动物方法替代。尽管现有批准的用于 BoNT 活性测量的体外方法是特定于产品的，并非所有用户都可以免费使用，但“结合和切割”（BINACLE）测定可能成为一种广泛适用的替代方法。该方法根据其特定的受体结合和蛋白水解特性对活性 BoNT 分子进行量化，并可应用于欧洲市场上的所有 BoNT 产品。

在这里，我们描述了一项可转移性研究的结果，其中在四个实验室的 BINACLE 检测中测试了相同的 BoNT 样品。所有参与者都成功地执行了该方法并观察到明确的剂量反应关系。测定变异性在可接受的范围内。这些数据表明 BoNT BINACLE 检测是可靠的，可以直接在实验室之间转移。因此，它们为未来的研究提供了适当的基础，以进一步证实 BINACLE 检测对 BoNT 产品效力测定的适用性。