Tail snip

Technique

Snipping the tail surgically is a relatively crude method of blood sampling and should be avoided where possible, or only undertaken under terminal anaesthesia, because of the potential pain and permanent damage to the tail. The saphenous vein and tail vein are more appropriate routes of sampling for most studies and strains.

Where other routes cannot be used, tail snipping should be performed aseptically, taking no more than 1 mm from the tip of the tail using a new scalpel blade. A local anaestheic cream (e.g. EMLA cream) should be applied to the site 30 minutes prior to blood sampling. Depending on the age of the mice, general anaesthetic may be more appropriate.

Approximately 10 ul can be obtained per sample by gently 'milking' the tail. Normally no more than a maximum of four samples should be taken in any 24 hour period. Where multiple samples are collected this should be done by removing the scab or blood clot from the tail tip. Blood flow can be stopped by dabbing the tail tip with a clean tissue and bleeding usually stops immediately.

Conscious mice need to be restrained either manually or using a restraint tube. This can cause stress and the duration of restraint should be kept to a minimum. Where a restraint tube is used, it should be appropriate for the size of the mouse in order to avoid damage to the tail, testes and limbs. All forms of restraining equipment should be frequently washed to prevent pheromonally-induced stress or cross-infection.

Summary

Number of samples No more than four blood samples should be taken within any 24-hour period.
Sample volume 10 ul
Equipment New sterile scalpel blade
Adverse effects
  • Infection <1%
  • Haemorrhage
Staff resource One person is required to take the sample.

Resources and references

  • A good practice guide to the administration of substances and removal of blood, including routes and volumes.
  • Ness RD (1999) Clinical pathology and sample collection of exotic small animals. The Veterinary Clinics of North America: Exotic Animal Practice. 2(3),  591-620
  • Lucas RL, Lentz KD, Hale AS (2004) Collection and preparation of blood products. Clinical Techniques in Small Animal Practice. 19(2),  55-62
  • Tuli JS, Smith JA, Morton DB (1995) Corticosterone, adrenal and spleen weight in mice after tail bleeding, and its effect on nearby animals. Laboratory Animals. 29(1), 90-95
  • Nemzek JA, Bolgos GL, Williams BA, Remick DG  (2001) Differences in normal values for murine white blood cell counts and other hematological parameters based on sampling site. Inflammation Research. 50(10),  523-527
  • Schnell MA, Hardy C, Hawley M, Propert KJ, Wilson JM (2002) Effect of blood collection technique in mice on clinical pathology parameters. Human Gene Therapy. 13(1), 155-161
  • Methods of blood collection in the mouse.
  • Removal of blood from laboratory animals and birds.
  • Durschlag M, Wurbel H, Stauffacher M, von Holst D (1996) Repeated blood collection in the laboratory mouse by tail incision - modification of an old technique. Physiology and Behaviour. 60(6), 1565-1568

Tail snip technique in other animals

The tail snip technique is only appropriate for use in the mouse.

All blood sampling techniques in the mouse

Click here for information on blood vessel cannulation in the mouse Click here for information on tail vessel microsampling in the mouse Click here for information on tail vein blood sampling in the mouse Click here for information on saphenous vein blood sampling in the mouse Click here for information on retro-orbital blood sampling techniques in the mouse Click here for information on abdominal/thoracic blood vessel blood sampling in the mouse Click here for information on cardiac puncture blood sampling in the mouse Click here for information on schedule 1 stunning followed by decapitation in the mouse Click here for information on decapitation blood sampling techniques in the mouse