This article presents the various applications of plasma separation (plasmapheresis) from whole blood, consisting mainly of plasma and platelet collections from donors and therapeutic plasma purification with emphasis on membrane processes. It also describes the various available techniques for these applications. Plasma collection from donors is mainly achieved by continuous centrifugation because of its low cost, with a centrifugal bowl placed in an extracorporeal circuit or with a small cylindrical rotating filter the Autopheresis C from Baxter. Therapeutic plasma purification can be carried out by first separating plasma from blood by membrane filtration and replacing it by an albumin solution of fresh frozen plasma obtained from donors. Other described techniques consist of selective removal of a pathogeneous molecule by secondary filtration, chemical adsorption, or immunoadsorption. Respective advantages and drawbacks of these methods are discussed. The last section describes a method of blood salvage during surgery by washing and concentration of red blood cells by a plasmapheresis membrane.
