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What is "Fraction V?"
Fact: Today, virtually no bovine albumin, and certainly
none on a commercial scale, is produced using the full five fraction "Cohn" ethanol
method, although albumin continues to go by the nickname "Fraction V".
The often misunderstood terms "Fraction V" and "Cohn"
as applied to albumin have their origins in the
1940s, when plasma fractionation was first invented.
Human blood plasma was an important life-saving
medical treatment, but also a highly perishable
commodity that was often in short supply. A great
need existed for material that could serve the
life-saving functions of blood plasma but would
be easier and more practical to store, inventory,
transport and administer. Methods were sought
to divide, or "fraction," the blood plasma into
its active components to find stable substitutes
for whole plasma.
Dr. Edwin J. Cohn, a researcher at Harvard University,
developed the true, original Cohn "fractionation"
procedure in the 1940s. Dr. Cohn determined that
different proteins in the blood could be separated
from each other by using different temperatures
and biochemical conditions and by the use of solvents
like ethanol. His method used these biochemical
techniques to separate the blood plasma into five
fractions. The fifth fraction was albumin, the
most abundant protein in the blood, which is why
albumin is often referred to as "Fraction V."
Albumin was an excellent substitute for human plasma.
When administered to wounded soldiers or other
patients with blood loss, it helped expand the
volume of blood and led to speedier recovery.
What's more, Cohn's method was gentle enough so
the protein retained its biological activity.
Recognizing the importance of this discovery,
the government immediately stepped in and "asked"
the major pharmaceutical companies of the time
to commercialize Dr. Cohn's fractionation process.
Later, there were many modifications and improvements
to the method, and it was also applied to the
production of animal albumin. Additional changes
came about as researchers found new applications
for bovine albumin in diagnostics, cell culture,
microbial culture and biochemical research. Many
of the new methods used heat, rather than solvents
as the main fractionation technique. Others used
acetone or salts like ammonium sulfate to separate
the albumin from the other plasma components.
One leftover of albumin history is that manufacturers
may continue to refer to their method as "Cohn Fractionation,"
although the manufacturing process and the products
bear little actual resemblance to the original.
For many decades, the Cohn ethanol fractionated products
have been widely accepted, but the reasons for
performance have been little studied or understood,
and the manufacturing processes have never been
modernized. Proliant identified many areas for
potential improvement.
Compared to modern purification methods, Traditional Cohn
fractionation is dangerous and environmentally
unfriendly (ethanol is an organic solvent and
a highly explosive, controlled substance), unsanitary
(requires open tanks and filter presses that increase
the possibility of contamination) and may be too
gentle to kill certain kinds of viruses that require
heat inactivation. Also, since there is no heating
step, the BSA is often contaminated with immunoglobulins,
which causes regulatory problems in pharmaceutical
production and can interfere with diagnostic assays.
Finally, current "Cohn" products are made by a
process that has changed little in over 50 years
and there are many inefficient or inconsistent
practices built into the procedure.
Proliant began unprecedented study into the current methods
of BSA production and the reasons for differences
in product suitability. For six years, the company
has been researching the production and performance
of Bovine Serum Albumin, developing and perfecting
more modern fractionation methods. We have learned
to remove and isolate the other plasma components,
similar to Cohn's original process, but using
cutting-edge separation techniques.
Our goal has been to match high-technology, economical
manufacturing with equivalent or superior product
performance. As a result we now produce high purity
diagnostic grades and Cohn Fraction V Analog Culture
Grade Albumin. We are able to harvest highly purified
BSA and other plasma proteins from the same plasma
stream, as well as isolate, enhance and add back
the precise co-factors to make an analog of Cohn
ethanol fractionated albumin suitable for cell
and microbial culture.
Back to Proliant Bovine Serum Albumin
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