This Phase 1 project will result in development of pigments, tattoo equipment and procedures for visual and instrumental identification of dark colored rodents. The B6C3F1 brown mouse will be used as a model. Various black and colored pigments will be evaluated along with light sources for visual reading of tail tattoos. In addition, optical character recognition scanning of tattoos will be employed for instrumental identification. An in vitro mammalian cell cytotoxicity test will be conducted on selected pigments. Phase 2 will involve life-time safety and efficacy studies on the pigments in mice and other laboratory animals and development of audio-video technician training programs in the use of these new techniques. Rapid, permanent and humane visual and instrumental identification systems for laboratory animals will increase the efficiency of animal research in toxicology, cancer, ageing and other important human and animal health problems. Worldwide markets for such equipment now exist.