FETAX Assay for Evaluation of Developmental Toxicity.

The frog embryo teratogenesis assay Xenopus (FETAX) test is a development toxicity screening test. Due to the small amount of compound needed and the capability to study organogenesis in a short period of time (96 h), FETAX test constitutes an efficient development toxicity alert test when performed early in drug safety development. The test is conducted on fertilized Xenopus laevis mid-blastula-stage eggs over the organogenesis period. Compound teratogenic potential is determined after analysis of the mortality and malformation observations on larvae. In parallel, FETAX test provides also information concerning embryotoxic effect based on larva length.