Animal Care and Use Program University of California, Berkeley

BLOOD COLLECTION TECHNIQUES AND LIMITS

Table of Contents
1. Purpose & Responsibilities
2. General Procedures
a. Rodent (Mouse and Rat) Procedures
b. Rabbit and Guinea Pig Procedures
3. Training
4. Blood Collection Limits
5. References

1. Purpose
This document outlines the preferred methods for collecting blood from animals
and blood collection volume and frequency limits. Blood collection for
experimental purposes must comply with the investigator’s Animal Care and Use
Committee (ACUC) approved protocol, including approved collection techniques,
volumes, and frequencies. The Office of Laboratory Animal Care (OLAC)
veterinary staff trains investigators in various collection techniques. The
veterinary staff may collect blood for veterinary care purposes using accepted
clinical techniques ensuring volumes collected do not adversely affect animal
health.

2. General Procedures
New, sterile needles must be used for each venipuncture. Do not reuse needles
between animals or between collection episodes.

Electric heat pads/lamps should not be used for vasodilation. Please consult with
OLAC veterinary staff or training coordinator for safe and effective vasodilation
methods.

Amputating digits for the collection of blood is incompatible with the humane care
and use of laboratory animals and is not permitted.

Requests to use alternative blood collection methods not listed in Table 1,

including transection of vessels or tail clipping, may be considered following
consultation with an OLAC veterinarian. The alternate method must be approved
in the ACUC approved protocol. Survival blood collections may be performed as
outlined in Table 1 (see next page).

Non-survival exsanguinations require administration of surgical levels of

anesthetic or lethal doses of euthanasia agents prior to collection (injectable
agent or carbon dioxide [CO2]). Survival blood collection from the heart must be
conducted under general anesthesia and is not permitted without scientific
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Animal Care and Use Program University of California, Berkeley
justification and competency certification by the OLAC veterinary staff or training
coordinator prior to performing the technique independently.
Table 1.

Species Recommended site for blood collection

Tail vein or artery, lateral saphenous vein, facial vein
Mouse* Retroorbital sinus subject to stipulations outlined in this guideline and
in the animal use protocol.
Tail vein or artery, saphenous vein, lateral saphenous vein, jugular vein
Rat* Retroorbital sinus subject to stipulations outlined in this guideline and
in the animal use protocol.
Rabbit* Marginal ear vein (small volumes), auricular artery (large volumes)

Ear vein, saphenous vein

Guinea pig* Anterior vena cava collection subject to stipulations outlined in this
guideline and in the animal use protocol.

*Cardiac collection subject to stipulations outlined in this guideline and in the animal use

a. Rodents (Mouse and Rat)

i. Preferred sites for blood collection from mice and rats include tail veins,
saphenous veins (hind limb), or, with proper training, the facial vein and
jugular vein (competency certification by OLAC required prior to
performing this technique independently). These techniques may be
performed in conscious animals. Use of the saphenous vein requires
clipping the fur from the area around the vein and swabbing with 70%
alcohol prior to puncture.

ii. Retro-orbital blood collection must be performed under general

anesthesia.
1. Survival retro-orbital blood collection is discouraged but may be
approved with robust scientific justification. When approved,
survival retro-orbital blood collection must include the
administration of an antibiotic ophthalmic and topical anesthetic to
both eyes to minimize pain and distress and prevent desiccation
and infection. Individuals performing retro-orbital blood collection
must be adequately trained and certified for competency by OLAC
prior to performing this technique independently due to the
potential for significant complications.

2. Sufficient time must be provided to allow the eye to heal before it is

re-used for blood collection. This generally requires 4 weeks for
recovery to minimize pathology in orbital tissues, including
hemorrhage, inflammation, and infection.

3. If this technique must be performed more than once on one animal,

alternating eyes at each blood collection is required.
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b. Rabbits and Guinea Pigs

i. The ear veins are often the preferred sites for blood collection from
rabbits. Rabbits become sensitive to ear manipulation and can
become resistant to repeated ear venipuncture. Ear venipuncture
may be performed in conscious animals but use of topical
anesthetics, such as EMLA cream, may reduce this resistance and
promote animal welfare. Use of the auricular (ear) artery may be
necessary for collecting larger volumes. Use of the ear vein may
require clipping the fur from the area around the vein and
swabbing with 70% alcohol prior to puncture.

ii. Marginal ear veins may be available for collecting small quantities
of blood from guinea pigs. The ear must be swabbed with 70%
alcohol prior to puncture.

iii. Cardiac puncture for blood collection requires general anesthesia,

as does collection of blood from the guinea pig anterior vena cava.
Experimental survival cardiac or vena cava blood collection
requires scientific justification and approval in the animal use
protocol.

3. Training
OLAC offers training for blood collection in a variety of laboratory species. In
addition, OLAC provides blood collection services for investigators for a nominal
fee. Retro-orbital and jugular vein, as well as survival intracardiac blood
collection requires competency certification by the OLAC veterinary staff or
training coordinator prior to performing these techniques independently.

Please refer to ACUC pre-approved verbiage for Blood Collection Procedures

for further details regarding blood collection procedures in select species.

4. Blood Collection Limits

The ACUC limits one time survival blood collection to 15% of an animal’s blood
volume in most circumstances. Serial blood sampling limit vary by species,
strain, and frequency of blood collection as outlined in Tables 2 and 3. The
ACUC may require monitoring for anemia (using assays such as hematocrit
and/or serum protein levels) when repeated collections or collection of larger
volumes are required. Blood collected for diagnostics or other veterinary
procedures must be considered when evaluating total volume available for
experimental use. In all cases blood collection volumes should be limited to the
minimum volume that will allow for successful experimentation or diagnostics.

(See Tables 2 & 3 on next page)

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Table 2. (Source: Fox et al. 2002; Diehl et al 2001)

Blood Blood Blood Volume

Species Volume Mean Volume Range (average)
(ml/kg) (ml/kg) 7.5% 10% 15%
Mouse
58.6 55-80 110µl 146µl 220µl
(25 g average weight)
Rat (250 g) 64 58-70 1.2 ml 1.6 ml 2.4 ml
Rabbit (4 kg) 56 44-70 17 ml 22 ml 34 ml
Nonhuman primate
56 55-75 34 ml 45 ml 67 ml
(NHP; 8 kg)

Table 3. (Source: Diehl et al., 2001)

Single sampling Multiple sampling

% Circulatory blood
% Circulatory blood Approximate Approximate recovery
volume removed
volume removed recovery period period
(cumulative volume)
7.5% 1 week 7.5% 1 week
10% 2 weeks 10-15% 2 weeks
10-15% 4 weeks 20% 3 weeks

5. References
• Diehl, K.H., Hull, R., Morton, D., Pfister, R., Rabemampianina, Y., Smith, D.,
Vidal, J.M., & van de Vorstenbosch, C. (2001). A Good Practice Guide to the
Administration of Substances and Removal of Blood, Including Routes and
Volumes. Journal of Applied Toxicology, 21, 15–23.
• Fox, J.G., Anderson, L.C., Loew, F.M., Quimby, F.W. (Eds.). (2002). Laboratory
Animal Medicine (2nd ed.). New York City, NY: Academic Press
• Hem, A., Smith, AJ, & Solberg, P. (1998). Saphenous Vein Puncture for Blood
Sampling of the Mouse, Rat, Hamster, Gerbil, Guinea Pig, Ferret, and Mink.
Laboratory Animals, 32, 364-68

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