Blood components

Red cell components are obtained by centrifugation of whole blood donations and removing most of the plasma. The red cells may be resuspended in an additive solution (e.g. SAG-M) to prolong storage and are filtered to remove most leucocytes. Red cells are used to treat anaemia and to replace blood loss from trauma or surgery.

Platelets are either produced by pooling buffy coats separated from whole blood donations or collected by apheresis. One apheresis donation can make up to three doses of platelets. Typically used for treatment of bleeding due to either severely decreased platelet production or functionally abnormal platelets (e.g. inherited platelet disorders).

Clinical fresh frozen plasma (FFP) is either separated from a single donation of whole blood or collected by apheresis. Usually used for patients with coagulopathy who are bleeding or at risk of bleeding.

Cryodepleted plasma is the supernatant left after cryoprecipitate has been removed from plasma. May be used for plasma exchange in thrombotic thrombocytopenic purpura (TTP). It may also be a practical alternative to FFP in some cases.

Cryoprecipitate is prepared by slow thawing of frozen plasma and recovering the cold‑insoluble precipitate, which is then refrozen. Used in major haemorrhage protocols to replace fibrinogen and in the treatment of fibrinogen deficiency or dysfibrinogenaemia.

Some blood components undergo additional manufacturing or testing steps to meet the clinical needs of certain patients, including washing, freezing, irradiation, phenotyped red cells, HLA/HPA-compatible platelets, and splitting into paediatric components.

Serum eyedrops are made from clotted whole blood donations for use by patients suffering from severe ocular surface disorders who do not respond to conventional therapies.