Plasmapheresis is the removal, treatment, and return of (components of) blood plasma from blood circulation. It is thus an extracorporeal therapy. The method can also be used to collect plasma for further manufacturing into a variety of medications.During plasmapheresis, blood is initially taken out of the body through a needle or previously implanted catheter. Plasma is then removed from the blood by a cell separator. Three procedures are commonly used to separate the plasma from the blood cells.