Revised Rodent Genotyping Guidelines
An important change in the genotyping guidelines relates to the use of analgesia following tail clipping. The revised guidelines stipulate that for mice greater than 16 days or rats greater than 14 days of age, local anesthesia of the tail or general anesthesia of the animal is required. Use of post-procedural analgesia following tail snipping is optimal. Note that dipping the tail in ice-cold ethanol for at least 10 seconds prior to tail snip and/or application of bupivacaine to the snipped tail as a local anesthetic is recommended. Also, note that only a minimal amount of tail tissue should be removed, generally 2-3 mm, and never more than 5 mm (regardless of animal age).
All new protocols and three-year revisions of protocols must immediately adhere to the revised genotyping guidelines. Existing protocols that stipulate procedures that deviate from the revised guidelines must come into compliance with the revised guidelines by July 1, 2017. No modifications of such protocols are needed, although all investigators are expected to comply with the revised guidelines by July 1.
Investigators with questions about the revised guidelines can contact the IACUC Office or the DLAR veterinarian assigned to their animal facility for more information.