The use of living animals is an important way to solve a medical problem. Researchers continually seek other models to understand the human organism, study disease processes, and test new therapies. In seeking quicker and not so expensive ways to look for biological information that can be applied to human disease, scientists sometimes study simpler things such as bacteria, fruit flies and a few other things. Researchers have spent many years learning how to sustain cells, tissues and organs from animals and humans outside the body to under ....