Development a high-throughput zebrafish embryo acute toxicity testing method based on OECD TG 236

Abstract

The Organization for Economic Co-operation and Development (OECD）Test Guideline (TG) 236 for zebrafish embryo acute toxicity testing was adopted for chemical toxicity assessment in 2013. Due to the increasing demand for prediction and evaluation of the acute toxicity using zebrafish embryos, we developed a method based on OECD 236 test guideline with the aim to improve the testing efficiency. We used 4–128 cell stage zebrafish embryos and performed an exposure assay in a 96-well microtiter plate, observing the lethality endpoints of embryos at 48-h postexposure. A total of 32 chemicals (two batches) were used in the comparison study. Our results indicated that the logarithmic LC₅₀ (half lethal concentration) obtained by the modified method exhibited good correlation with that obtained by the OECD 236 testing method, and the R² of the linear regression analysis was 0.9717 (0.9621 and 0.9936 for the two batches, respectively). Additionally, the intra- and inter-laboratory coefficient of variation (CVs) for the LC₅₀ from the testing chemicals (17 chemicals in second batch) was less than 30%, except for CuSO₄. Therefore, the developed method was less time-consuming and demonstrated a higher throughput for toxicity testing compared to the prior method. We argue the developed method could be used as an additional choice for high-throughput zebrafish embryo acute toxicity test.

Keywords:

• Zebrafish embryo
• OECD 236
• acute toxicity
• comparison
• throughput

Acknowledgments

The authors thank Pauline Wong, Stella Yiu, and Godfrey Chan of Vitargent for zebrafish colony maintenance and laboratory operation, and the participating laboratories for their commitment and most valuable contributions.

Author contributions

XPC designed and coordinated the study; SSX designed, analyzed, and wrote the paper; All authors participated the experiments. All authors reviewed the results and approved the final version of the manuscript.

Disclosure statement

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Additional information

Funding

The work described in this paper was supported by Innovation and Technology Commission, The Government of the Hong Kong SAR under Grant PsH/009/19 and PsH/008/19, and supported by Encouragement of Interdiscipliary Project of Guangxi Normal University under Grant 2021JC005.