A system for implanting laboratory mice with light-activated microtransponders.

The mouse is the most commonly used laboratory animal, accounting for up to 80% of all mammals used in research studies. Because rodents generally are group-housed, an efficient system of uniquely identifying individual animals for use in research studies, breeding, and proper colony management is required. Several temporary and permanent methods (for example, ear punching and toe clipping) are available for labeling research mice and other small animals, each with advantages and disadvantages.