About Animal Identification
There are several methods available for identifying research mice and other small animals. Temporary and permanent methods are available to the researcher.
Permanent Identification Methods
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.
Ear tagging requires a special applicator to place an “earring” or metal tag with an identification number in the pinna of a mouse or rats ear. Since tags are relatively large and mouse ears develop quickly, ear tagging is primarily used on weanling and older mice. The applicator tip and ear tags should always be disinfected before use.
Subcutaneous implanting an RFID microchip is a method of permanently identifying an animal. Microchips are about the size of a grain of rice and transmit a unique alphanumeric code to the RFID. The codes are easily distinguished by the electronic reader. Since the implants are relatively large, it is not recommended for newborn mice. Implanting is ideal for identifying rodent weanlings and adults.