Human plasma contains a large number of valuable therapeutic proteins, such as albumin, immunoglobulins and other factors. The process of extraction and purification of these proteins is called plasma fractionation.

The presence of other substances or particles in plasma may result in the instability of the products and the obstruction of the final filters. Therefore, prefilters are necessary to eliminate those impurities before chromatography and ultrafiltration. Final filters are used for the sterilizing filtration of heat-sensitive proteins.