Methods of Animal Identification
Suggested methods for identification of rodents include:
- Ear punch/notch
- Ear tag
- Microchip transponders
- Tattoo
- Sharpie marker for temporary identification
- Toe clipping in very limited circumstances
Procedures to be followed if individual identification is used:
Ear punch/notch: Rodents should be firmly restrained and a sharp punch or scissor used on the pinna (ear). Removed tissue may also be used for DNA analysis. The ear punch schematic should be standardized by the laboratory to ensure correct interpretation of the identification number.
Ear Tags: Individually numbered ear tags are widely used for rodent identification. The tag must be appropriately sized for the species/age of rodent. Proper placement of the tag is required to ensure it does not cause irritation or trauma to the ear. ULAR staff is available to demonstrate and train personnel on proper placement location.
Microchip Transponders: Microchips are available for use in rodents and have the ability to transmit body temperature, activity, etc… in addition to providing a unique identification number. The chips are placed subcutaneously or intraperitoneally using aseptic technique. When microchips are used, scanners should be readily available to confirm animal identity.
Tattoo (ink injection): Rodent tattoo devices are available through ULAR and can be used to permanently mark the skin on the tail, toes, or other sites as needed. ULAR staff should be consulted for training on this method of identification. Tattooing may be best accomplished under anesthesia. Improper technique will result in fading of the tattoo.
Toe-clipping: This method of identification is discouraged by the Guide for the Care and Use of Laboratory Animals. The IACUC must be assured that the procedure is performed in the most painless and humane way. Scientific justification is required if this procedure is performed. Animals over 14 days of age require anesthesia if this method is to be used.
