Rodent Tail Biopsy

IACUC Policy

The IACUC regards tail biopsy as potentially painful procedure that may be done only in a manner consistent with this policy. Only the minimum amount of tissue necessary for the objective should be taken from the youngest animal possible. Tail biopsy can be performed on conscious neonate rodents as a means for genotype analysis/determination.

Tail Biopsy Procedure:

Mice 21 days of age or younger and rats 14 days of age or younger:

1.  Rodent pups should be held in gloved hands.

2.  Amount of tissue collected should be kept to a minimum.

a.  A general guideline is to remove 5 mm or less.  Removal of 2 mm at an early age (< 21 days) likely yields sufficient DNA for multiple PCR reactions.*

3.  Very sharp scissors must be at least disinfected with accelerated hydrogen peroxide disinfectant for a minimum of 5 minutes initially.

a.  The instrument should be cleaned with alcohol after each animal.

4.  Bleeding should be immediately controlled by gentle fingertip pressure.

5.  Pups should be quickly returned to their dams. Cages containing tail biopsied neonates should be checked 5 minutes after tail tip removal to confirm complete hemostasis.

 6.  Tails may be biopsied without anesthesia for this age group.

Mice older than 21 days and rats older than 14 days:

1.  Rodents should be handled with gloved hands.

2.  Amount of tissue collected should be kept to a minimum (5 mm or less).

3.  A sterile scalpel or straight blade must be used and replaced after 5 uses or sooner if it becomes dull.

4.  Bleeding should be immediately controlled by gentle fingertip pressure.

5.  Anesthesia is required for this procedure and must be described in an IACUC approved protocol.

Researchers should familiarize themselves with genotype assays and select techniques providing the needed information with the least amount of tissue/sample collected in the least invasive manner.

Exceptions to this policy will be reviewed by the IACUC for approval consideration.

*Guidelines for Tissue Collection for Genotyping Mice and Rats (NIH Office of Intermural Research)

 

Approved: May 2005

Revisions Approved: 8/2008, 12/2012, 10/2017, 6/2019