OECD to develop new guidance to minimise fish use in some studies, based on NC3Rs-led work.
The OECD has agreed to develop new international guidance for measuring the biomarker vitellogenin (VTG) in fish, which is used to assess whether environmental chemicals disrupt the endocrine system. VTG testing is currently performed in species such as zebrafish, medaka and fathead minnow, but results can vary widely between laboratories, even in control animals. This variability can lead to wasted animals and the need for repeat studies, with some VTG test programmes using around 3,000 fish.
The new guidance will set best practices for laboratory methods and statistical analysis to improve reliability, reduce unnecessary repeat testing, and standardise approaches globally. This work is the result of several years of NC3Rs-led collaboration with industry, contract research organisations and regulators.
Dr Natalie Burden will lead the UK’s contribution to the project alongside an OECD expert working group. Her recent work has also shown the potentially huge animal and financial impact of future endocrine disruptor testing under EU REACH, with up to tens of millions of animals and billions of euros in costs potentially involved.
Development of the VTG guidance will begin in early 2026, and once completed it will become the international reference for VTG testing, improving data quality while reducing fish use.
Credit: NC3Rs