Abstract Toxicity testing with animals has limitations with regards to cost, time, reliability, and animal welfare. We propose to develop a novel toxicological screening approach in a single animal format for quickly assessing the safety of chemicals with reduction of animal use and improved animal welfare. We will develop a new testing procedure with which we could perform tests in only one animal to obtain information on the effective doses, impacted tissues, and organs, and toxicodynamics of toxicants, which usually need experimenting on hundreds of animals, months to years efforts, and enormous biochemical and pathological analyses in the traditional toxicological study. The breakthrough technique is a reporter system for real-time mapping cellular damage caused by chemical substances in the whole body. It can detect the toxic effects of substances as early as cellular damage occurs in the body. Whereas in traditional animal testing, adverse effects only become detectable/measurable in animals exhibiting significant degrees of adverse health effects after receiving high doses of test chemicals. Instead of taking the animal body as a "black box" in the traditional testing, our new technique enables real-time monitoring responses to a chemical by making the animal body transparent for directly observing adverse effects at the cellular level.