I: Background and Purpose:
The IACUC has developed the following guidelines for blood collection from mice and rats. All blood sampling, including frequency
and volume, must be in an approved Animal Use Protocol (AUP). Deviations from these techniques, such as
increase in blood volume or frequency to be collected, must be approved by the
IACUC.
II: Related Policies
and Guidance
Policy 529-349: Guidelines for Rodent Anesthesia and Analgesia
Policy 529-350: Guidelines for Rodent Euthanasia
III: Procedures
A. Blood Collection Sites in Mice and Rats
- Tail Vein - Sample collection by nicking the vessel is easily performed but produces a sample of variable quality that may be
contaminated with tissue products.
- Saphenous vein – Blood collection can be performed by piercing the saphenous vein with
a needle. General anesthesia is not required, although effective restraint is
necessary.
- Facial vein (mice only) - This procedure can be performed rapidly with
no general anesthesia. Approximately 200 ul of blood can be obtained
by using a 20 gauge (or
smaller) hypodermic needle or lancet.
- Jugular vein (rats only) – Suitable for collecting medium to large
volume and high- quality blood sample.
This procedure can be performed
without anesthesia, although
the use of anesthesia greatly facilitates the procedure.
- Retro-Orbital Blood Collection - This procedure should
be performed by highly experienced and trained personnel and must be performed
under general anesthesia. Blood collection should
not be more frequent than every 2 weeks and alternate eyes used
for sampling. The maximum number of blood collections per animal is two per
eye.
- Cardiac puncture - Blood sampling
by cardiac puncture
is only allowed
as a terminal procedure in anesthetized animals.
B.
Volume and Frequency
- Approximately 10% of the total blood volume
can be safely removed every
2 - 4 weeks, 7.5% every
week, and 1% every 24 hours. The
acceptable quantity and frequency of blood sampling is dependent on
the circulating blood volume of the animal and the red blood cell (RBC) turnover
rate (RBC life span of the mouse:
38-47 days. RBC life span of the rat: 42-65 days). The approximate circulating blood volume
(CBV or total blood volume TBV) of
adult rodents varies with species and body weight [mouse 63 to 80 ml/kg (mean
72 ml/kg) and rat 58-70 ml/kg (mean 64 ml/kg)].