Blood Collection Limits

The Animal Research Committee (ARC) limits survival blood collection to 1.25% (1.25 ml/100 g) of the animal’s current body weight. The frequency of blood collection depends on the volume collected. If the maximum volume is collected, as specified above, blood may be collected once every two weeks, or with multiple blood draws, the maximum amount may be collected over a two week period. The ARC may require monitoring for anemia (using assays such as hematocrit and/or serum protein levels) when more frequent collections or collection of larger volumes are necessary. The minimum amount of blood that will allow for successful experimentation should be collected at any time.

General Procedures

Amputating digits for the collection of blood is not permitted and is incompatible with the humane care and use of laboratory animals. Requests to use alternative blood collection methods, including transection of vessels or tail clipping, may be considered following consultation with a DLAM veterinarian. The alternate method must be approved by a DLAM veterinarian and in the ARC approved protocol.

Survival blood collections may be performed without general anesthesia if peripheral blood vessels are used (please refer to Table 1).

Nonsurvival exsanguinations require administration of lethal doses of pentobarbital (or other injectable anesthetic), or exposure to inhaled anesthetic or carbon dioxide (CO2). Survival blood collection from the heart is not permitted without scientific justification and must be conducted under general anesthesia.

Rodent Procedures

Please refer to Table 1.

Retroorbital blood collection must be performed under general anesthesia, followed by the administration of an antibiotic ophthalmic ointment to both eyes to prevent desiccation and infection; however, when a short-term anesthetic such as isoflurane is used, application of antibiotic ophthalmic ointment is only necessary for the affected eye. Individuals performing retroorbital blood collection must be adequately trained due to the potential for significant complications.

The ARC does not recommend retroorbital blood collection in rodents for serial sampling (i.e., repeated blood collections over a period of several minutes or hours) unless scientifically justified. Generally, sufficient time (2 weeks is recommended) must be provided to allow the eye to heal before it is re-used for blood collection, as this procedure has been associated with histopathologic and clinical changes in orbital tissues, including hemorrhage, inflammation, and infection.

As an alternative to retroorbital puncture, the ARC recommends the use of the lateral saphenous vein, located on the hindlimb, for blood collection. This technique may be performed in conscious animals and requires clipping the fur from the area around the vein and swabbing with 70% alcohol prior to puncture. [2] Repeated sample collection is permitted, provided the volume does not exceed 1.25% (1.25 ml/100 g) of the animal’s current body weight every two weeks.


The Division of Laboratory Animal Medicine (DLAM) offers free training for blood collection in a variety of laboratory species. In addition, DLAM provides blood collection service for investigators for a nominal fee. Contact DLAM training staff for more details on blood collection training. For fee-for-service blood collection by DLAM technicians, contact DLAM technical services.

Table 1. Recommended Blood Collection Sites in Laboratory Animals

The following are the recommended blood collection sites on species commonly used at UCLA. For species not included on this chart or for alternative blood collection methods, please contact a DLAM veterinarian for consultation.

Species Recommended site for blood collection
Mouse Tail vein or artery, lateral saphenous vein, retro-orbital sinus**, cardiac*.
Rat Tail vein or artery, saphenous vein, retro-orbital plexus**, lateral saphenous vein, cardiac*.
Rabbit Marginal ear vein (small amounts), auricular artery (larger amounts), cardiac*.
Guinea pig Ear vein, saphenous vein, anterior vena cava**, cardiac*.
Cat Cephalic vein, femoral vein, jugular vein, recurrent metatarsal vein, cardiac*.
Dog Cephalic vein, femoral vein, jugular vein, recurrent metatarsal vein, cardiac*.
Pig Ear vein, jugular vein, anterior vena cava**.
NHP Cephalic vein, saphenous vein, femoral vein, jugular vein.
Bird Ulnar (brachial) vein, right jugular vein, medial metatarsal vein, cardiac*.
Chinchilla Cephalic vein, femoral vein.

* Cardiac puncture should be performed only on animals under anesthesia and it is recommended only as a terminal procedure.

** These techniques must be performed only on anesthetized animals. When anesthesia is not an alternative the procedure needs to be scientifically justified and approved by the ARC.


  1. Van Herck, H. et al. Histological Changes in the Orbital Region of Rats After Orbital Puncture. Laboratory Animals (1991b) 26: 53-58.
  2. Hem, A.; Smith, AJ; Solberg P. Saphenous Vein Puncture for Blood Sampling of the Mouse, Rat, Hamster, Gerbil, Guinea Pig, Ferret, and Mink. Laboratory Animals (1998) 32:364-368.
  3. Tappa, B., Amao, H., Takahashi, K. W. A simple method for intravenous injection and blood collection in the chinchilla (Chinchilla laniger). Lab Anim 1989(23):73-75.
  4. C. Terrance Hawk, Steven Leary, Timothy Morris. Formulary for Laboratory Animals. Blackwell Publishing, Ames, IA (2005), pp. 155-156.

Approved 8/89; Revised 4/28/03, 3/22/04, 7/26/04, 8/3/05, 10/23/06, 6/14/10, 2/22/13; Updated 12/16/15