There are several methods available for identifying research mice and other small animals. Temporary and permanent methods are available to the researcher.Temporary IdentificationA felt tip marker can mark the ear or tail for several days. Dyes may be used to color a patch of fur; which will generally last several weeks, however restricted to albino and light colored animals. Another method is to shave a patch of fur on the back or side of the animal.Permanent IdentificationMethods for permanently identifying rodents include ear punching, ear tagging, tattooing, and subcutaneously implanting a numerically coded transponder microchip.
Ear punching is commonly used for identification of rodents and involves using a special punch to either produce a small (0.5 to 2 mm) notch near the edge or to punch a hole in the middle of the ear. Always test before animal use. The cutting edge of the punch should be disinfected or the entire punch should be autoclaved