Chemical Screening and Toxicity Testing

The chemical space is vast, encompassing potentially billions of natural and synthetic molecules, which are for the most part uncharted with regard to their pharmaceutical, therapeutic, or toxicological potential. Determining the biological efficacy or harm of these chemicals presents both an enormous opportunity and a challenge to society. Chemical screening is the first step in development of novel therapeutical agents. The process typically involves searching chemical libraries for small organic molecules that have biological activities that might be useful in addressing pathological conditions for which there are unmet medical needs. Toxicology, in contrast, investigates effects of chemicals that are harmful to human or animal health or the environment in general. Xenopus is an exceptionally effective animal model system for assaying both potential therapeutic and toxicological effects. Here I introduce protocols that detail how Xenopus extracts, embryos, and tadpoles can be used in chemical screening and toxicity testing.