Prediction of acute fish toxicity:

The use of zebrafish embryos for the prediction of fish acute toxicity of chemicals and effluents has become an increasingly accepted alternative to the animal test with juvenile or adult fish. Up to 5 days after fertilization, until the onset of independent feeding, the embryo does not fall under animal welfare regulation because of its very early developmental stage. Yet, it holds the complexity of a whole organism.

Over the past years many studies showed the excellent correlation of LC50s obtained in fish and zebrafish embryos. In Germany, the zebrafish embryo instead of fish are used for effluent testing according to ISO 15088 since 2005. In July 2013, the OECD guideline 236 for testing of chemicals using the zebrafish embryo was adopted.

In the zebrafish embryo toxicity test according to OECD 236, the freshly fertilized embryos are exposed to the test item in 5 concentrations over a course of 96 h. Every 24 h, four apical endpoints of acute toxicity are recorded and the LC50 is calculated based on the 96 h observation.

Apart from the requirements of this standard test, we offer flexible test design according to your needs by e.g. extension of test duration up to 120 h and additional observation and recording of sub-lethal endpoints. We further hold strong expertise in the establishment of optimal test designs with respect to chemical stability.

  • Knöbel et al., 2012, Env. Sci. Technol. 46(17), 9690−9700. Predicting adult fish acute lethality with the zebrafish embryo: Relevance of test duration, endpoints, compound properties, and exposure concentration analysis.
  • Internatonal Standard ISO 15088:2007(E), Water quality – Determination of the acute toxicity of waste water to zebrafish eggs (Danio rerio), International Organization for Standardization, 2007
  • OECD Guideline for Testing of Chemicals. Test No. 236: Fish Embryo Acute Toxicity (FET) Test; Organization for Economic Cooperation and Development: Paris, 2013

Other endpoints:

The fish embryo development is a complex process. Exposures to environmental samples or chemicals do not necessarily cause macroscopic detectable lethal or sub-lethal effects.

However, effects, which can eventually impact on the fitness of the organism, can be deciphered on the molecular level. To observe such effects, we offer gene expression analysis of a wide variety of molecular biomarkers, reflecting a broad range of cellular responses such as endocrine disruption, general stress response, biotransformation, and immune regulation.

To observe neurotoxic responses of chemicals in fish we offer different behavioral tests with up to 120 h old zebrafish embryos.