Fractionation (partitioning) are the processes by which plasma proteins are recovered from human plasma, namely, plasma is separated into it component proteins. Each process is based on the inherent differences in proteins. These processes isolate, purify and concentrate human plasma proteins and include:

Precipitation and adsorption
Depth filtration
Centrifugation
Chromatography

$Technician samples plasma fractionation solution$

Fractionation involves changing the conditions of the product intermediates (e.g., the temperature, the ionic strength or the acidity) so that proteins become insoluble and precipitate. The CSL Behring plasma-derived proteins coagulation factor concentrates are produced using a modified Cohn-fractionation. First the frozen plasma is thawed and pooled. The proteins, which are insoluble under cold conditions (FVIII, vWF and FI (fibrinogen) are separated by centrifugation and contained in the so-called cryoprecipitate. In the next step, the vitamin K dependant coagulation factors (F II, VII, IX and X) are adsorbed from the supernatant and after that factor XIII precipitation takes place through the addition of alcohol. Immunoglobulins and albumin are precipitated by increasing the alcohol concentration.

Precipitation is the formation of a solid in a solution during a chemical (or physical) reaction. The solid is filtered out. Adsorption is a process that occurs when a gas or liquid solute accumulates on the surface of a solid or, more rarely, a liquid (adsorbent), forming a molecular or atomic film (the adsorbate). Adsorptives are selectively transferred from the fluid phase to the surface of insoluble, rigid particles suspended in a vessel or packed in a column. Depth filtration is the process by which the precipitate is held back. Centrifugation is a process that involves the use of the centripetal force for the separation of mixtures. Chromatography is the collective term for a family of laboratory techniques for the separation of mixtures. It involves passing a mixture dissolved in a "mobile phase" through a stationary phase, which separates the analyte to be measured from other molecules in the mixture and allows it to be isolated. This purification process effectively reduces the viral load. For increased safety CSL Behring implemented additional inactivation/elimination steps, such as pasteurization and virus filtration.