- Resources and references
- Tail vein technique in other animals
- All blood sampling techniques in the mouse
Tail vein sampling is suitable for all strains but is more difficult in black or pigmented mice. For competent individuals, it is quick and simple to perform. This technique may require the animals to be warmed in order to dilate the blood vessel prior to taking the sample. This can be stressful and can cause dehydration due to salivation, in addition to increasing metabolic rate, which may affect the experimental data. As a result, other routes such as saphenous vein sampling should be used where possible and, in particular, where there is a need to take multiple samples. View a video of the mouse tail vein sampling technique below.
The lateral tail vein is usually used and 50 ul to 0.2 ml of blood can be obtained per sample depending on the size of the animal and specific requirements. The tail may need to be washed with diluted Hibiscrub (1%) in order to see the blood vessel.
To avoid bruising and damage to the tail, normally no more than two blood samples should be taken per session and in any one 24-hour period. Where it is necessary and justifiable to take more, the use of temporary or surgical cannulation methods should be considered. The number of attempts to take a blood sample should be minimised (no more than three needle sticks in any one attempt) and sufficient time should be given for the tail to recover between blood sampling sessions. Alternate sides of the tail should be used and successive needle punctures moved towards the tail base.
If it is necessary to warm the animal, a warming cabinet should be used (39oC for up to 10 minutes). Mice should be carefully monitored, including checking for signs of dehydration. The time the mouse is in the warming cabinet should be recorded and the cabinet should be calibrated regularly to avoid hyperthermia; digital displays should not be relied upon. It is important to ensure the temperature in the cabinet is uniform and that there are no 'hot spots'. Male mice may need to be warmed singly to avoid fighting.
The lateral tail vein is usually accessed approximately one-third along the length of the tail from the tail tip, moving towards the base of the tail for multiple samples. An aseptic technique should be used. It is recommended that a local anaesthetic cream (e.g. EMLA cream) should be applied to the site 30 minutes prior to blood sampling. Animals need to be restrained which can cause stress and therefore the duration of restraint should be minimised. 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.
Blood flow should be stopped by applying finger pressure on the soft tissue. A finger should be placed at the blood sampling site for approximately 30 seconds before the animal is returned to its cage.
|Number of samples||One or two blood samples can be taken per session and in any 24-hour period, depending on sample volume. This limit also applies to microsampling.|
|Sample volume||50 ul to 0.2 ml|
|Equipment||25G - 27G needle or lance|
|Staff resource||One person is required to take the blood sample if a tube restrainer is used. For large groups of animals more staff members are required.|
|Other||Mice may be warmed, to dilate the blood vessel. Care should be taken to avoid hyperthermia and dehydration|
- 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
- Saphenous vein puncture for blood sampling of the mouse, rat, hamster, gerbil, guinea pig, ferret and mink.