Separation and storage of blood components

Whole blood is separated into several components

All types of donations (whole blood units, thrombapheresis units, plasmapheresis units) are now systematically depleted for leucocytes (whole blood by filtration, aphaeresis units by the aphaeresis apparatus itself or by filtration). Leukocytes are eliminated to avoid immunological side effects, to remove the cellular source of some viruses (like CMV) and prions, and to ameliorate blood conservation.

After filtration, the whole blood donation is separated into several components:

Packed red blood cells

Packed red blood cells from a donation of 450 ml of whole blood are obtained after centrifugation and plasma removal; the red cells are then suspended in a nutritive solution.
Storage: 2-6°C up to 42 days.

Packed red cells & fresh frozen plasma

Fresh frozen plasma

Fresh frozen plasma is obtained after centrifugation of whole blood and red cell removal, or through direct separation (plasmapheresis).
The plasma must be frozen within 8 hours after collection in order to preserve coagulation factors and other plasma proteins.

Because plasma can be stored for a long time, plasma is kept in quarantine until the donor comes back for a new donation so that he can be tested again for the infectious disease markers. This gives optimal security because (early) infections undetectable at the moment of donation have now become apparent.

Storage: ≤ 30°C for up to 2 years

Plasma can also be fractionated and processed into stable blood products, such as albumin, immunoglobulins, coagulation factors, ...

Platelets

Platelets are mainly obtained through thrombapheresis. Platelet products formerly obtained from a mix of more than 10 buffy coats can now be obtained from a single thrombapheresis of about 40 minutes.
Storage: 20-24°C for 5 days, under constant mixing of the bags (platelets aggregation occurs in the cold and in absence of agitation).