Bags of sheep blood
Sheep raised for bleeding
Blood agar plates
National Cancer Institute image
A bloody good idea
- First blood transfusion
The first fully-documented blood transfusion was carried out by
Dr. Jean Baptiste Denys on June 15, 1667. He tranfused the blood
from a sheep into a 15-year old boy who later died. The doctor
was charged with his death.
The first successful blood transfusion did not occur until 200
years later in 1818. By this time, doctors had discovered mixing
blood types posed serious health risks.
- Sheep as blood donors
Different kinds of culture media can be used to isolate microorganisms
and diagnose infection. Horse and sheep blood are the most widely
used animal blood products in culture media. The choice of the
animal is largely traditional, with the U.S. and much of continental
Europe preferring sheep blood. While some sheep blood is obtained
from abattoirs, some sheep are raised specifically to produce
blood for biomedical purposes.
At 18 weeks, they reach their peak antibody level and are then bled
every four weeks in a fashion similar to what happens at the Red
Cross. Animals are first bled at about 20 months of age and generally
remain in the research flock until they are 7.5 years old.
Sheep as drug factories
Protherics is a drug development company specializing in critical
care products derived from sheep polyclonal antibodies. The
raw material (serum) for their products comes from their sheep
flock in South Australia. The 4,500 strong first cross Merino/Border
Leicester wethers are immunized every four weeks for 18 weeks
to produce antibodies against either a snake venom or particular
Once the blood has been harvested, it is transported to the manufacturing
facility where the bags are spun in centrifuges to separate the
red blood cells from the serum, containing the antibodies. It
is then filtered, frozen, and exported to the parent company manufacturing
site in Wales. The antibodies are extracted and purified to form
the end product.
Products include North American rattlesnake anti-venom, an antidote
for overdoses of the heart drug Digoxin, CytoFab for the
control of sepsis-syndrome or septic shock, a Prolarix,
a novel anti-cancer drug. Protherics is one of a handful of
companies worldwide that uses sheep to produce polyclonal antibodies.
<== SHEEP PRODUCTS