Fraction V and Cohn (Or is it Cone?)

Blog entry

OK folks, today we power through our “Month of Albumin” with a history lesson. I like these because when I do these, I usually learn something new and entertaining. For example, I had no idea that Alexander Fleming was a slob. Next to learning that Einstein failed algebra the first time, that news on Fleming stands as definitive proof that I can still procure that Nobel Prize that the committee seems to keep away from my meaty little paws. So. What juicy tidbits will we learn today? I have no idea. I haven’t written it yet.

Many people see “Fraction V” with their BSA information. Sometimes it’s even accompanied by “Cohn’s.” Sometimes you see “Cohn’s” and “Fraction V” is nowhere to be found. SO what gives? Why are we at the mercy of the vendors who seem to name their BSA whatever they feel like naming it? Who knows. What I do know, however, is that sometime in the 1930s, Edwin Cohn figured out a way to purify serum albumin by taking advantage of different proteins’ solubility in ethanol, different pH, and different temperatures. In essence, Cohn started off with blood plasma, and treated it with different concentrations of ethanol and tweaked the pH and the temperature. After doing this, he ended up with five major precipitates (fractions). The 5th fraction was indeed, pure albumin.

While there have been subsequent methodologies developed since WWII to isolate and purify albumin, the Cohn fractionation method remains the gold standard. Which is why Gemini offers a Cohn Fraction V cold ethanol purified grade. After all, it not only stood the test of time, but this method preserves the biological activity of albumin, which means this stuff works and does what it’s supposed to do, as if it never even left the cow. Pretty cool in my book!


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