Plasma Fractionation
Human plasma is the source of over 700 proteins of considerable therapeutic value such as albumin, clotting factors, immunoglobulins, fibrinogen and others. The process used to extract and purify these proteins is known as plasma fractionation. Classical fractionation employs selective precipitation of proteins by manipulation of solution pH, ionic strength, temperature and ethanol content. Modern fractionation increasingly employs chromatography to make higher purity and better activity products. Contamination of plasma compounds can cause product instability as well as plugging downstream filters and should be removed via prefiltration.
Clarification is used to remove contaminants prior to chromatography or UF steps, while sterilizing-grade filtration is a final step used to reduce bioburden and to sterilize heat labile proteins. A critical step, viral clearance, ensures the removal of viruses known to have contaminated source plasma such as parvovirus, hepatitis and HIV. Specialty antibodies such as hyper-immune globulin typically include a viral clearance filtration step in their manufacturing process.
