According to the company, it can now determine levels of T3 (triiodothyronine) and T4 (thyroxine) hormones in serum from rats at days 4 and 13 of age using ultra-high pressure liquid chromatography coupled to a high-end tandem mass spectrometer (UHPLC-MS/MS) for detection.
The method enables completion of thyroid hormone tests in accordance with OECD guidelines.
“All chemical manufacturers and importers must adhere to OECD test guidelines as a mandatory requirement when undertaking studies to complete their REACH dossiers,” Sunetha Diaram, Head of Bioanalysis, Envigo, told us.
“Without robust data in accordance with the guidelines, they may be unable to manufacture or import their new and existing chemicals inside the EU.”
Development and validation
Diaram explained a key challenge was developing robust extraction and detection methodologies to acquire the sensitive levels required using minimal sample volume.
“This could have presented some difficulties as the related studies involve sample collection from rat fetus and pups where sample collection volumes are a challenge,” he explained.
Additionally, because T3 and T4 are endogenous molecules, the company had to develop an appropriate analytical validation study design to minimize interference and contamination.