The rat is an excellent cell transplantation model. In accordance with the innovative development of in vivo bioimaging technology, over the last decade we have been developing an engineered rat system based on transgenic technology and have been demonstrating the usefulness of the system with genetically encoded imaging probes such as fluorescent and luminescent proteins. In cooperation with the Japan Society for Organ Preservation and Medical Biology (President: Professor T. Asano), we have also been using luciferase-Tg rats for research into organ preservation and cell transplantation. In this minireview, we introduce the results obtained recently by using these powerful experimental tools during international collaboration in cell transplantation research.