A method for the cryopreservation of red blood cells using hydroxyethyl starch as a cryoprotectant

A simple, quick, inexpensive and long term method of cryopreserving human red cells using hydroxyethyl starch (HES) as a cryoprotectant is described. No sophisticated equipment or skilled labour is required. As HES is a plasma expander, it does not have to be removed prior to transfusion, thereby obviating the requirement for a washing stage. This allows 60 units/h to be prepared. As the microbiological integrity of the system is maintained, there is potential for prolonged storage post-thaw at 4 degrees C. Recoveries of 99% and 30 min saline stabilities in excess of 91% have been consistently achieved. P50O2 and 2,3DPG values are not significantly decreased.