Technical Guidelines for Use

Prepared By:  Dr. Grant MacGregor
(Last updated 5/20/2001)

Materials

1. Squirt bottle with 70% ethanol

2. Surgical scissors (e.g. Fine Science Tools (FST, (http://www.finescience.com) ) catalog # 14090-11; Fine Iris Scissors for digits and FST Tough-cut tungsten carbide catalog # 14558-11 for tails)

3. Suitable non-porous work surface – e.g. resin bench top or stainless steel surface in hood.

4. Appropriate disinfectant

5. Small Kimwipe

6. Fresh cage bottom with bedding

7. Toe-clipping ID chart

8. 1.5ml Eppendorf tubes in rack

9. Glass bead sterilizer (e.g. FST cat # 18000-45; FST 250 Portable hot bead sterilizer)

10. Appropriate injectable anesthetic as approved by the IACUC

11. Soldering iron with fine tip (e.g. RadioShack 40 watt)

Notes

1. Anesthesia MUST be used as approved by the IACUC

2. If using Avertin, animals should be at least 4 weeks old. Experience has indicated that animals younger than this age do not routinely tolerate Avertin anesthesia well. Use of an alternative anesthetic agent is indicated with younger animals.

3. Prior to use, thoroughly clean and disinfect the work surface where the procedure is to be performed by washing with an appropriate disinfectant. Protective mask, gown and gloves should be worn.

4. Where necessary, use a fine pair of surgical scissors (e.g. FST catalog # 14090-11) to perform the toe biospies. Experience suggests that it is worthwhile to use quality scissors that will cut cleanly and not require frequent sharpening. Use a robust pair of surgical scissors (e.g. FST Tough-cut tungsten carbide catalog # 14558-11) to perform the tail biospies. Prior to use on the first animal, the clean scissors can be sterilized by placing the tips in a glass bead sterilizer (e.g. FST cat # 18000-45) for 20 seconds. Between animals, the scissors may be cleaned using a fresh Kimwipe soaked in 70% ethanol. This serves to disinfect and remove traces of tissue from the previous animal, which could serve as a source of DNA contamination. It is unnecessary to sterilize the scissors in the glass bead unit between animals.

5. The wounds will bleed. Cauterize the wounds by application of a pre-heated soldering iron tip to the wound. Digits that have not been amputated should not be touched with the soldering iron.

6. Animals should be placed in an open cage on a slide warmer set to 37 deg C until they regain consciousness. This will minimize mortality due to anesthesia-associated hypothermia.

7. Rebiopsy of an animal should not be conducted within 48 hours of a first procedure.

8. Digital amputation is not recommended as an identification procedure in weanling and older animals.  Ear notching, ear tags, or implanted transponders are preferred.  Requests for deviations and amputation/toe snips of altricial animals beyond the 12 day threshold must be scientifically justified and will be considered on a case-by-case basis by the IACUC at the time of protocol review or in response to a request for protocol modification.  Convenience or poor planning are inadequate justifications for toe snipping of adult animals and alternatives should be used. 

9. Limited quantities of numbered ear tags may be obtained from the Emory University Transgenic Mouse Core Facility. Ear punches may be purchased from general scientific vendors (e.g. VWR).

The IACUC Guidelines for Biopsy Procedures to Facilitate Identification and DNA-based Molecular Genotyping of Rodents can be found at:  http://www.emory.edu/IACUC/pdfs/BiopsyPolicy.pdf

Method

1. Plug in the soldering iron and allow it to reach operating temperature.

2. Count the number of animals on which biopsies are to be performed. Label this number of Eppendorf tubes using a permanent sharpie. It is advisable to label the top and side of each tube.

3. Weight each animal and anesthetize using an approved anesthetic. Leave animals in their home cage on a slide warmer until they lose consciousness.

4. Assuming you are right handed, using the thumb and first finger of your left hand, lift the mouse firmly but carefully by the skin at the nape of the neck. Position the animal so that it is facing you. The mouse can be supported by placing your third and fourth fingers underneath its hindquarters.

5. Working quickly, but carefully, hold the animal’s tail over Eppendorf tube and carefully cut approximately 0.5cm, allowing the tail tip to fall into the tube.

6. Carefully apply the soldering iron to the tail. Contact for up to three seconds may be necessary for tails. Ensure the bleeding has ceased before replacing the mouse in its cage.

7. Permanently identify the animal as approved and appropriate.

8. Wipe the forceps and scissors with a fresh KimWipe, soaked in ethanol between each animal.

9. Monitor the animals until they have regained consciousness. Check the animals 3 hours later to determine if they are experiencing discomfort or pain. Indications for such include vocalization, excessive grooming of tail-tip or digits, hyper or inactivity, hunched posture and or piloerection. If the procedure is performed properly, such cases should be rare. If they occur, consult with the attending veterinarian or euthanatize the animal in compliance with experimental endpoints using a method approved by the IACUC.

• Biopsy Techniques for ID & Genotyping
  • Adult Rodents
  • Altricial Neonates
• Genetic Monitoring
• Pathogen Screening of Biological Materials
• Rodent Health Surveillance Program
  • Mouse Sentinel Program Overview
  • Mouse Health Surveillance Results
  • Rat Sentinel Program Overview
  • Rat Health Surveillance Results
• Rodent Quarantine Program
• Mouse Antibody Production (MAP) Testing
• Form for Shipping Rodents