Tissue Sampling Policy for Rodents Genotyping

IACUC Policy: 014-06, Effective Date: 02/25/2005, Last Revision: 03/17/2023

Overview/Purpose

Analysis of rodent DNA may be necessary to verify the genetic composition of individual animals. Common collection sites include tail-snip/biopsy and ear punch/notch although hair roots, fecal pellets, and buccal swabs are less invasive and should be considered if very small quantities of DNA could be used for genotyping.

Requirements

Tissue sampling for genotyping should be done as early as possible in the lifespan of the mouse to minimize the potential for pain/distress. Tissue sampling must be performed using sharp devices to avoid tissue crushing. Instruments must be cleaned between individual animals to minimize cross-contamination of genetic material. Animals must not be returned to the home cage until hemostasis is achieved.

• Ear Punch/Notch Procedure: Manual restraint without anesthesia is acceptable. The ear punch/notch can also serve as a method of individual animal identification. The amount of tissue collection using this procedure is limited.
• Tail-Snip/Biopsy Procedure: When tail tissue (<5mm) is collected in mice up to and including 21 days of age, anesthesia is not required. General anesthesia is however required if removing greater than 5 mm of tissue (regardless of age) or if performing a tail-snip/biopsy in rodents 22 days or older. In all cases, hemostasis must be accomplished using digital pressure or styptic powder (Kwik-Stop ®). If the animal is anesthetized, cautery may be used for hemostasis via a cautery pen, or via heated instruments used to the collect the sample (scissors or blade heated in a hot bead sterilizer. Tail-snip/biopsy of mice 22 days or older must be described as a protocol activity and approved by the IACUC

If other tissues or blood are being collected and used for genotyping, this must be described as a protocol activity and be approved by the IACUC.

Additional Resources 

• Boivin et al, 2016. A highly efficient strategy to determine genotypes of geneticallyengineered mice using genomic DNA purified from hair roots http://journals.sagepub.com/doi/abs/10.1177/0023677216646088
• Bonaparte D, Cinelli P, Douni E, Herault Y, Maas M, Pakarinen P, Poutanen M, Lafuente MS, Scavizzi F. 2013. FELASA guidelines for the refinement of methods for genotyping genetically-modified rodents: a report of the Federation of European Laboratory Animal Science Associations Working Group. Lab Anim. Jul;47(3): 134-45.
• Boivin, GP, et al. 2013. Genotyping DNA Isolated Using Cross-Linked Iminodiacetate Sytrene Divinylbenzene Copolymer Beads. J Am Assoc Lab Anim Sci 52:682.
• Braden-Weiss, G.C., Brice, A.K., Hankenson, F.C. 2011. Minimizing the impact of tail biopsy in preweanling laboratory mice: inhaled isoflurane compared with topical anesthetics. J Am Assoc Lab Anim Sci 50: 736-737.
• Broome, R. L., L. Feng, Q. Zhou, A. Smith, N. Hahn, S. M. Matsui, and M. B. Omary. 1999. Non-invasive transgenic mouse genotyping using stool analysis. FEBS Letters 462:159-60.
• Burkhart, C. A., M. D. Norris, and M. Haber. 2002. A simple method for the isolation of genomic DNA from mouse tail free of real-time PCR inhibitors. Journal of Biochemical
  and Biophysical Methods 52:145-9.
• Cinelli, P., A. Rettich, B. Seifert, K. Burki, and M. Arras. 2007. Comparative analysis and physiological impact of different tissue biopsy methodologies used for the genotyping of laboratory mice. Laboratory Animals 41:174-84.
• Gaire K, Maquart G, Merlin JF. 2017.Animal-friendly mouse genotyping using direct PCR. Thermoscientific White Paper.
• Garzel LM , Hankenson FC, Combs J, Hankenson KD. 2010. Use of quantitative polymerase chain reaction analysis to compare quantity and stability of isolated murine DNA. Lab Anim (NY), 39(9): 283-289.
• Hankenson, F.C., Braden-Weiss, G., Blendy, J.A. 2011. Behavioral and activity assessment of laboratory mice (Mus musculus) after tail biopsy under isoflurane anesthesia. J Am Assoc Lab Anim Sci 50:686-94.
• Hankenson, F. C., L. M. Garzel, D. D. Fischer, B. Nolan, and K. D. Hankenson. 2008. Evaluation of tail biopsy collection in laboratory mice (Mus musculus): vertebral ossification, DNA quantity, and acute behavioral responses. J Am Assoc Lab Anim Sci 47:10-8.
• Jones CP, Carver S, Kendall LV. 2012 . Evaluation of common anesthetic and analgesic techniques for tail biopsy in mice. J Am Assoc Lab Anim Sci. Nov;51(6):808-14.
• Okada M, Miller TC, Roediger J, Shi Y, Schech J. 2017. An Efficient, Simple, and Noninvasive Procedure for Genotyping Aquatic and Nonaquatic Laboratory Animals. JAALAS Vol56(5): 570-573.
• Paluch, LR, Lieggii, CC, Dumont, M, Monette, S, Riedel, E, Lipman, NS. 2014. Developmental and Behavioral Effects of Toe Clipping on Neonatal and Preweanling Mice with and without Vapocoolant Anesthesia. JAALAS Vol 53(2): 132-140.