Embryoid Body Test: A Simple and Reliable Alternative Developmental Toxicity Test.

The increasing emphasis on animal welfare and ethics, as well as the considerable time and cost involved with animal testing, have prompted the replacement of many aspects of animal testing with alternative methods. In the area of developmental toxicity, the embryonic stem cell test (EST) has played a significant role. The EST evaluates toxicity using mouse embryonic stem cells and somatic cells and observes the changes in heartbeat after cardiac differentiation. Nevertheless, the EST is a relatively complex testing process, and an in vitro test requires a long duration. Several attempts have been made to develop a more straightforward testing method than the EST, with improved reproducibility and accuracy, leading to the development of the embryoid body test (EBT) Unlike the EST, which involves cardiac differentiation stages, the EBT verifies toxicity by measuring the changes in the area of the embryoid body. Despite its short testing period and simple procedure, the EBT offers high accuracy and reproducibility and is fully validated through two rounds of validation, making it ready for practical application. The EBT is expected to play a crucial role in the rapidly increasing demand for alternative methods to animal testing, particularly for screening early developmental toxicity.