Fractionation is the process of separating and purifying therapeutic proteins from plasma.
Various treatments are used to progressively separate proteins from plasma. These include the addition of alcohol or salts, and changing the acidity level of the solution. After each step, some of the proteins are selectively collected and further purified. While the demand for plasma derivatives is increasing, each of the four major producers, Bayer, Aventis, Alpha Therapeutics and Baxter is currently operating at or near manufacturing capacity. It is the most widely used viral inactivation method in the world.